SEASON TWO - BRYAN MANGIN

Units of measurement

Introduction

Today in this lesson we will take a look at the units of measurement. In this course you will not study a list of words on a topic but rather a list of kanji, used as units of measurement, and learn how these units of measurement are used.
This course directly follows the one on numeral classifiers so I’m assuming that you have followed this course and that you have understood it. This is very important before moving on to this one. If you need to revise the previous course to refresh your memory, do not hesitate to back off before returning here.
Numeral classifiers and units of measure are two very different things that many learners confuse since, in both cases, we place a kanji after a number when reading it in its Sino-Japanese reading. The main difference is that :
1/ Numeral classifiers are used to count things, animals, people by putting them into categories. They indicate a quantity.
2/ Units of measurement are simply used to indicate a unit of measure when creating nouns.

If this introduction seems a little obscure to you, no worries, we’ll get started right away and you’ll understand.
I’ll start by giving you about ten kanji that can be used with numbers to indicate things. All we’ll see here :
1/ Can be used with the suffix . and the prefix . ダイ to create ordinal numbers.
2/ Responds to the same pronunciation peculiarities that we saw in the course on number classifiers.
3/ And, replacing the Sino-Japanese numbers by the interrogative noun . なん, we can of course create interrogative words that we can themselves use with +, +, +でも as you know how to do now.

The list of measurement units

I give you below the list of ten units of measurement with, for each one, explanations and examples of the specific use for each.

. カイ . Floor
Used to count floors (first floor, second floor...). Be careful, what is equivalent to the ground floor for us is equivalent to the first floor in Japan. Take a look at the few examples :
一階 . イッカイ . The ground floor
二階 . ニカイ . The first floor
三階 . サンカイ . The second floor
四階 . よんカイ . The third floor
...
七階 . ななカイ . The sixth floor
Note : don’t forget the little superstition that hangs over the number « four » in Japan.

. ダン . Stair step; level, rank, grade
Used to count the stair steps, levels and grades, particularly in sport. For example, in martial arts, if we mean the fifth « dan », we’ll say :
五段 . ゴダン . The fifth « dan »

. . Story, episode
Used to count episodes, especially in a TV series. This unit of measurement comes from the word . はなし which means « story ». This unit of measure is used with the prefix . ダイ like this :
第一話 . ダイイチワ . The first story, the first episode
第二話 . ダイニワ . The second story, the second episode
第三話 . ダイサンワ . The third story, the third episode
第四話 . ダイよん. The fourth story, the fourth episode
第五話 . ダイゴワ . The fifth story, the fifth episode
第六話 . ダイロクワ . The sixth story, the sixth episode
第七話 . ダイなな. The seventh story, the seventh episode
第八話 . ダイハチワ . The eighth story, the eighth episode

Now let’s take a sentence as an example. If we mean :
The eighth Harry Potter story.
We’ll say :
ハリー・ポッターの第8話。

Now if we mean :
The seventh episode of Dragon Ball Super.
We’ll say :
ドラゴンボール超の第7話。

. ハク . Overnight stay
Used to count the number of nights, for example, when booking a room in a hotel or hostel :
十泊 . ジュウハク . Ten nights

. サイ . Age in years
Used to count the age in years. Not to be confused with the kanji of . とし which simply means « the year » in general but is not a unit of measure.
Also written with the kanji often used by children because the official kanji is rather complicated to remember at the beginning.
If we mean for example « ten years old », we’ll say :
十歳 . ジュウサイ . Ten years old

If we mean for example « twenty years old », we’ll say :
二十歳 . ニジュウサイ . Twenty years old
OR
二十歳 . はたちサイ . Twenty years old

If we mean for example « eighteen years old », we’ll say :
十八歳 . ジュウハチサイ . Eighteen years old

Now let’s make a sentence. If i mean « I am twenty eight years old » :
私は二十八歳だ . わたしはニジュウハチサイ. I am twenty-eight years old.

. ダイ . Generation
Used with the suffix . to count the generations. For example, if we mean « the second generation », we’ll say :
二代目 . ニダイ. The second generation
If we mean « the fourth generation », we’ll say :
四代目 . よんダイ. The fourth generation

. ショウ . Chapter, section
Used to count chapters, especially in a book. This unit of measurement is used with the prefix . ダイ like this :
第一章 . ダイイッショウ . The first chapter, the first section
第二章 . ダイニショウ . The second chapter, the second section
第三章 . ダイサンショウ . The third chapter, the third section
第四章 . ダイよんショウ . The fourth chapter, the fourth section
第五章 . ダイゴショウ . The fifth chapter, the fifth section
第六章 . ダイロクショウ . The sixth chapter, the sixth section
第七章 . ダイななショウ . The seventh chapter, the seventh section

. バン . Number
Used to indicate a position in a list. For example, to say « the number one » :
一番 . イチバン . The number one, the first
And we can continue like this with « the number two », « the number three », « the number four », « the number five »…
二番 . ニバン . The number two, the second
三番 . サンバン . The number three, the third
四番 . よんバン . The number four, the fourth
五番 . ゴバン . The number five, the fifth
六番 . ロクバン . The number six, the sixth
七番 . ななバン . The number seven, the seventh
八番 . ハチバン . The number eight, the eighth
Now, if we want to name a very specific element within a list like, for example, « the second fruit », « the third vegetable » or even « the fourth image », « the fifth chair »… we’ll follow the following pattern :
Number + . バン + suffix . + particle + name of the element in the list
二番目画像 . ニバンガゾウ . The second image
三番目. サンバンゾウ . The third statue
二番目果物 . ニバンくだもの . The second fruit
六番目椅子 . ロクバンいず . The sixth chair
十番目生徒 . ジュウバンセイト . The tenth pupil
七番目. ななバンいえ . The seventh house
二番目. よんバンねこ . The fourth cat
十一番目. ジュウイチバンいぬ . The eleventh dog
十四番目. ジュウヨンバン. The fourteenth tree
八四番目. ハチバンホン . The eighth book
There are, however, a few small exceptions to this pattern. For example, if we mean « the fifth avenue », « the third avenue », this time in Japanese we will « eat » the suffix . and the particle to say :
二番街 . ニバンまち . The second avenue
五番街 . ゴバンまち . The fifth avenue

In Japanese, sometimes there are certain words where we will simplify the expression. This happens sometimes, especially when it comes to commonly used phrases.

. バイ . Multiplier
Used to indicate how many times things have been multiplied. For example, to say « one time », « twice / two time », « thrice / three times », « four times », « five times », « six times », « seven times »… we’ll say :
一倍 . イチバイ . One time
二倍 . ニバイ . Twice / two times
三倍 . サンバイ . Thrice / three times
四倍 . よんバイ . Four times
五倍 . ゴバイ . Five times
六倍 . ロクバイ . Six times
七倍 . ななバイ . Seven times
八倍 . ハチバイ . Eight times

. カイ . Occurrence
Used to indicate occurrence, that is, the tendency for something to happen over and over again. For example, to say « thrice / three times », « four times », « five times », « six times », « seven times »… we’ll say :
一回 . イッカイ . One time
二回 . ニカイ . Twice / two times
三回 . サンカイ . Thrice / three times
四回 . よんカイ . Four times
五回 . ゴカイ . Five times
六回 . ロクカイ . Six times
七回 . ななカイ . Seven times
八回 . ハチカイ . Eight times

. . Occurrence, degree of temperature and angles
Also used to indicate occurrence, that is, the tendency for something to happen over and over again, but also the degree of temperature and angles. As much . カイ does not represent the degree at all, as much . represents both the occurrence and the degree of temperature and angles.
The difference between . カイ and ., about the occurrence, it is that . カイ is used for something that repeats itself on a regular basis and that we know will repeat itself over and over again on a regular basis. For example, a sporting event, a cultural celebration, a festival, a birthday. While . be used for something that is repeated but does not necessarily be repeated in the future. We don’t know if this something will repeat itself, maybe it will, maybe it won’t. For example, I’m dropping my plate for the third time in less than a week, but I don’t intend to drop it a fourth time.
So, to say « one time », « twice / two times », « thrice / three time », « four times », « five times », « six times », « seven times »… we’ll say :
一度 . イチド . One time
二度 . ニド . Twice / two times
三度 . サンド . Thrice / three times
四度 . よん. Four times
五度 . ゴド . Five times
六度 . ロクド . Six times
七度 . なな. Seven times
八度 . ハチド . Eight times

You will have noticed that in English, for the last three units of measurement, we use the word « times » to translate the idea of multiplication and occurrence. Like what, in English it’s very simple but in Japanese things are a bit more complicated.
This first introduction has allowed you to see that the way of using the units of measurement is exactly the same as for the numeral classifiers. But keep in mind the subtle difference that I explained to you in the introduction, it is very important. I would really like you to learn how to distinguish between numeral classifiers and units of measurement. If you make this effort, things will start to seem easier to you.

The units of measurement to express the duration

Now is the time to see the units of measure to express duration. Okay, this time, if you know your lesson entitled « read the time in Japanese », inside and out, you already know all the kanji we’re going to see with their Sino-Japanese pronunciations. Know already that, if we want to express a duration, we will take a number with its Sino-Japanese pronunciation and the pronunciation peculiarities that this will generate depending on the unit of measure chosen.

. ビョウ . Seconde
Used to express the duration in seconds. Here we are following the classic pattern. I give you some examples :
一秒 . イチビョウ . One second
二秒 . ニビョウ . Two seconds
三秒 . サンビョウ . Three seconds
四秒 . よんビョウ . Four seconds
五秒 . ゴビョウ . Five seconds
六秒 . ロクビョウ . Six seconds
七秒 . ななビョウ, シチビョウ . Seven seconds
八秒 . ハチビョウ . Eight seconds
九秒 . キュウビョウ . Nine seconds
十秒 . ジュウビョウ . Ten seconds
十五秒 . ジュウゴビョウ . Fifteen seconds
三十秒 . サンジュウビョウ . Thirty seconds

. フン . Minute
Used to express the duration in minutes. Here we are following the classic pattern. Pay attention to the particularities of pronunciation. I give you some examples :
一分 . イッ. One minute
二分 . ニフン . Two minutes
三分 . サン. Three minutes
四分 . よん. Four minutes
五分 . ゴフン . Five minutes
六分 . ロッ. Six minutes
七分 . ななフン, シチフン . Seven minutes
八分 . ハッ. Eight minutes
九分 . キュウフン . Nine minutes
十分 . ジュウ, ジッ. Ten minutes
十一分 . ジュウイッ. Eleven minutes
十二分 . ジュウニフン . Twelve minutes
十三分 . ジュウサン. Thirteen minutes
十四分 . ジュウよん. Fourteen minutes
十五分 . ジュウゴフン . Fifteen minutes
三十分 . サンジュッ, サンジッ. Thirty minutes

. . Hour
Used to express duration in hours. Here, we follow the classic pattern except that we will use the suffix . カン which makes it possible to differentiate the idea of the duration of the expression used to speak of the time that we read on a dial.
So, if we want to say « It’s five o’clock. », we’ll say :
五時 . ゴジ
But if we want to express a duration, always five hours but as a duration, we’ll say :
五時間 . ゴジカン
I give you some examples :
一時間 . イチジカン . One hour
二時間 . ニジカン . Two hours
三時間 . サンジカン . Three hours
四時間 . ジカン . Four hours
五時間 . ゴジカン . Five hours
六時間 . ロクジカン . Six hours
七時間 . ななジカン, シチジカン . Seven hours
八時間 . ハチジカン . Eight hours
九時間 . クジカン . Nine hours
十時間 . ジュウジカン . Ten hours
十一時間 . ジュウイチジカン . Eleven hours
十二時間 . ジュウニジカン . Twelve hours
十三時間 . ジュウサンジカン . Thirteen hours
十四時間 . ジュウよんジカン . Fourteen hours
十五時間 . ジュウゴジカン . Fifteen hours
三十時間 . サンジュッジカン . Thirty hours

. ニチ . Day
Used to express the duration in days. Here, we are following a somewhat particular pattern. We’ll use the suffix . カン which helps to differentiate the idea of duration from the expression used to talk about days in general. And in addition to that, you should know that the kanji of the day, , will be pronounced ニチ to say « one day » as a duration and without the suffix . カン. Then, for everything else from two to infinity if you want, the kanji of the day, , will be pronounced .
Take a look at the examples below :
一日 . イチニチ . One day
二日間 . カン . Two days
三日間 . サンカン . Three days
四日間 . カン . Four days
五日間 . カン . Five days
六日間 . カン . Six days
七日間 . ななカン, シチカカン . Seven days
八日間 . ハチカン . Eight days
九日間 . キュウカン . Nine days
十日間 . ジュウカン . Ten days
十一日間 . ジュウイチカン . Eleven days
十二日間 . ジュウニカン . Twelve days
十三日間 . ジュウサンカン . Thirteen days
十四日間 . ジュウよんカン . Fourteen days
十五日間 . ジュウゴカン . Fifteen days
三十日間 . サンジュッカン . Thirty days

. シュウ . Week
Used to express the duration during the week. Here we are following the classic pattern and we will use the suffix . カン as we did to express duration in hours and days. Pay attention to the particularities of pronunciation.
I give you some examples :
一週間 . イッシュウカン . One week
二週間 . ニシュウカン . Two weeks
三週間 . サンシュウカン . Three weeks
四週間 . よんシュウカン . Four weeks
五週間 . ゴシュウカン . Five weeks
六週間 . ロクシュウカン . Six weeks
七週間 . ななシュウカン, シチシュウカン . Seven weeks
八週間 . ハッシュカン . Eight weeks
九週間 . キュウシュウカン . Nine weeks
十週間 . ジュウシュウカン . Ten weeks
十一週間 . ジュウイチシュウカン . Eleven weeks
十二週間 . ジュウニシュウカン . Twelve weeks
十三週間 . ジュウサンシュウカン . Thirteen weeks
十四週間 . ジュウよんシュウカン . Fourteen weeks
十五週間 . ジュウゴシュウカン . Fifteen weeks
三十週間 . サンジュッシュウカン . Thirty weeks

. ガツゲツ . Month
Used to express the duration in months. Here, we will once again have a somewhat peculiar pattern. Well, if you know your lesson about the months of the year, you know that to say « January », « February », « March »… we say :
一月 . イチガツ, 二月 . ニガツ, 三月 . サンガツ
To express the duration in months, we are not going to use the suffix . カン. We are going to use a small feature unique to this case. For example, if we mean « one month » as a duration, we’ll say :
. ゲツ . ゲツ . One month

You have this funny little symbol that I put in orange, , and which is pronounced . It used to be a kanji, this one, . but which is no longer used to express the duration in months and has been replaced by this symbol , which makes this writing a bit odd but much easier to write and remember.
I give you some examples :
. イッゲツ . One month
. ゲツ . Two months
. サンゲツ . Three months
. よんゲツ . Four months
. ゲツ . Five months
. ロッゲツ . Six months
. ななゲツ , シチゲツ . Seven months
. ハッゲツ . Eight months
. キュウゲツ . Nine months
. ジュウゲツ . Ten months
十一. ジュウイッゲツ . Eleven months
十二. ジュウニゲツ . Twelve months
十三. ジュウサンシュウカン . Thirteen months
十四. ジュウよんゲツ . Fourteen months
十五. ジュウゴゲツ . Fifteen months
三十. サンジュッゲツ . Thirty months

Did you know ? The word « trimester » by definition equates to a duration of three months, so to say « trimester » in Japanese we say . サンゲツ . And to say « semester » in Japanese, which is equivalent to a duration of six months, we’ll say . ロッゲツ .

. ネン . Year
Used to express the duration in years. Here we are following the classic pattern and we do not have to use the suffix . カン. In fact, if we say 一年 . イチネン, literally means « year one ». Same, if we say 二年 . ニネン, literally means « year two ». And so on. But it’s usually very rare to talk about year one or year two... except in very special cases, in history for example (and really if you go back very far in time !). So, to express the duration in years, we can quite say 一年 . イチネン or even 二年 . ニネン… as long as the context make us to understand that we are talking about a duration, which is generally the case in over 90% of situations.
However, if you absolutely want to avoid any ambiguity, you can add the suffix . カン.
I give you some examples below with the suffix . カン in parentheses to show you that it is optional in most cases :
一年() . イチネン(カン) . One year
二年() . ニネン(カン) . Two years
三年() . サンネン(カン) . Three years
四年() . ネン(カン) . Four years
五年() . ゴネン(カン) . Five years
六年() . ロクネン(カン) . Six years
七年() . ななネン(カン), シチネン(カン) . Seven years
八年() . ハチネン(カン) . Eight years
九年() . キュウネン(カン) . Nine years
十年() . ジュウネン(カン) . Ten years
十一年() . ジュウイチネン(カン) . Eleven years
十二年() . ジュウニネン(カン) . Twelve years
十三年() . ジュウサンネン(カン) . Thirteen years
十四年() . ジュウネン(カン) . Fourteen years
十五年() . ジュウゴネン(カン) . Fifteen years
三十年() . サンジュッネン(カン) . Thirty years

Also note that the suffix . カン is optional to express the duration in seconds and minutes. So, you can very well say 秒間 . ビョウカン and 分間 . フンカン, always paying attention to the pronunciation peculiarities for the latter.

To count days, weeks, months and years

We have seen how to express duration in seconds, minutes, hours, days, weeks, months and years. Now we are going to learn how to count days, weeks, months and years.
You’ll see, there is nothing complicated, just follow the pattern shown :

1. To count the days

To count the days, I invite you to refer to the lesson on the number of days. Remember that the first ten days of the month have a rather special pronunciation.
Number + . ニチ + suffix .
一日目 . イチニチ. The first day
二日目 . ふつ. The second day
三日目 . みっ. The third day
四日目 . よっ. The fourth day
五日目 . いつ. The fifth day
六日目 . むい. The sixth day
七日目 . なの. The seventh day
八日目 . よう. The eighth day
九日目 . ここの. The ninth day
十日目 . とお. The tenth day
十一日目 . ジュウイチニチ. The eleventh day
十二日目 . ジュウニニチ. The twelfth day
十三日目 . ジュウサンニチ. The thirteenth day
十四日目 . ジュウよっ. The fourteenth day
十五日目 . ジュウゴニチ. The fifteenth day

2. To count the weeks

Number + . シュウ + suffix .
一週目 . イッシュウ. The first week
二週目 . ニシュウ. The second week
三週目 . サンシュウ. The third week
四週目 . よんシュウ. The fourth week
五週目 . ゴシュウ. The fifth week
六週目 . ロクシュウ. The sixth week
七週目 . ななシュウ, シチシュウ. The seventh week
八週目 . ハッシュウ. The eighth week
九週目 . キュウシュウ. The ninth week
十週目 . ジュウシュウ. The tenth week
十一週目 . ジュウイチシュウ. The eleventh week
十二週目 . ジュウニシュウ. The twelfth week
十三週目 . ジュウサンシュウ. The thirteenth week
十四週目 . ジュウよんジュウ. The fourteenth week
十五週目 . ジュウゴシュウ. The fifteenth week

3. To count the months

To count the months, there are two possible patterns. The first is the one below :
Number + . ゲツ + suffix .
For this pattern, you have this funny little symbol that I put in orange, , and which is pronounced .
月目 . イッゲツ. The first month
月目 . ゲツ. The second month
月目 . サンゲツ. The third month
月目 . よんゲツ. The fourth month
月目 . ゲツ. The fifth month
月目 . ロッゲツ. The sixth month
月目 . ななゲツ, シチゲツ. The seventh month
月目 . ハッゲツ. The eighth month
月目 . キュウゲツ. The ninth month
月目 . ジュウシュウ. The tenth month
十一月目 . ジュウ イッゲツ. The eleventh month
十二月目 . ジュウニゲツ. The twelfth month
十三月目 . ジュウサンゲツ. The thirteenth month
十四月目 . ジュウよんゲツ. The fourteenth month
十五月目 . ジュウゴゲツ. The fifteenth month

Then you have the second possible pattern :
Number + . バン + suffix .+ particle + . つき
一番目. イチバンつき . The first month
二番目. ニバンつき . The second month
三番目. サンバンつき . The third month
四番目. よんバンつき . The fourth month
五番目. ゴバンつき . The fifth month
六番目. ロクバンつき . The sixth month
七番目. ななバンつき . The seventh month
八番目. ハチバンつき . The eighth month
九番目. キュウバンつき . The ninth month
十番目. ジュウバンつき . The tenth month
十一番目. ジュウイチバンつき . The eleventh month
十二番目. ジュウニバンつき . The twelfth month
十三番目. ジュウサンバンつき . The thirteenth month
十四番目. ジュウよんバンつき . The fourteenth month
十五番目. ジュウゴバンつき . The fifteenth month

4. To count the years

Number + . ネン + suffix .
一年目 . イチネン. The first year
二年目 . ニネン. The second year
三年目 . サンネン. The third year
四年目 . よんネン. The fourth year
五年目 . ゴネン. The fifth year
六年目 . ロクネン. The sixth year
七年目 . ななネン, シチネン. The seventh year
八年目 . ハチネン. The eighth year
九年目 . キュウネン. The ninth year
十年目 . ジュウネン. The tenth year
十一年目 . ジュウイチネン. The eleventh year
十二年目 . ジュウニネン. The twelfth year
十三年目 . ジュウサンネン. The thirteenth year
十四年目 . ジュウよんネン. The fourteenth year
十五年目 . ジュウゴネン. The fifteenth year

The new interrogative nouns

We can finally move on to a more concrete use of everything we’ve just seen from the start, starting with the questions. We are going to create new interrogative words by replacing the Sino-Japanese numbers with the interrogative noun . なん.
Let’s start with a first list of interrogative nouns :
何階 . なんカイ . Which floor ? On what floor ?
何話 . なん. Which story ? / Which episode ?
何泊 . なんハク . How many nights ?
何歳 . なんサイ . How old ?
何代 . なんダイ . Which generation ?
何番 . なんバン . What number ?
何倍 . なんバイ . How many times ? (Multiplier)
何回 . なんカイ . How many times ? (Regular occurrence and knowing that it will happen again)
何度 . なん. How many times ? (Occurrence which will not necessarily recur)

Well, so far nothing special to say. Let’s move on :
何秒 . なんビョウ . How many seconds ?
何分 . なにブン . How many minutes ?
何時. なん. What time ?
何時間 . なんジカン . How many hours ?
何日 . なんニチ . How many days ?
何週 . なんシュウ . How many weeks ?
何月 . なんガツ . What month ?
. なんガツ . How many months ?
何年 . なんネン . How many years ?

What do we have here ? We have 何秒 . なんビョウ to ask the question « How many seconds ? », we have 何分 . なにブン to ask the question « How many minutes ? », and to ask the question « How many hours ? », we say 何時間 . なんジカン. Don’t worry, this is completely normal. We have seen that, to express time as duration, the suffix . カン is required, so to ask the question « How many hours ? », it makes sense to say 何時間 . なんジカン.
Then, to ask for the time, just say 何時 . なん. And you’ll notice above that I have put you the particle . Quite simply because, when we ask for the time, we are always asking for a specific point in time. Remember your course on the time complements.

Interrogative nouns + Particles = New words (again)

Remember, in the lesson entitled « Ask a Question in Japanese », we saw that we could combine interrogative nouns with particles to create new words.
Here, we will do it with the particle to indicate an absolute positive value :
+ (absolute positive value)
Let’s start with a first list of words :
何階. なんカイ. A few floors, several floors
何話. なん. Several stories, several episodes
何泊. なんハク. A few nights, several nights
何代. なんダイ. A few generations, several generations
何番. なんバン. A few numbers, several numbers
何倍. なんバイ. Several times (Multiplier)
何回. なんカイ. Several times (Regular occurrence and knowing that it will happen again)
何度. なん. Several times (Occurence which may not happen again)

Well, so far nothing special to say. Let’s move on :
何秒. なんビョウ. A few seconds, several seconds
何分. なにブン. A few minutes, several minutes
何時にも. なんにも. Anytime
何時間. なんジカン. A few hours, several hours, for hours
何日. なんニチ. A few days, several days
何週. なんシュウ. A few weeks, several weeks
何月. なんガツ. A few months, several months
何年. なんネン. A few years, several years

Indicate the frequency and duration in the past

Now we’ll take it up a notch and learn how to indicate a frequency in Japanese, that is, occurrence versus duration.
To understand more easily, we will start immediately by analyzing a first example :
一日に三回 . イチニチサンカイ . Three times per day
« Three times per day », this is an occurrence that occurs three times in a day.
Be careful not to go wrong when switching from English to Japanese and vice versa. Remember that the sentence construction in Japanese is reversed compared to English.
Note : In the sentence above, we assume that the occurrence is regular and we know it will happen again. But, of course, if it was an occurrence that might not happen again, we would have used the corresponding unit of measure.

Another example now :
一週間四回 . イッシュウカンよんサンカイ . Four times a week
« Four times a week », this is an occurrence that occurs four times in a week.
Once again, be careful not to go wrong.

Now, if we want to express a duration in the past by saying for example :
A week ago.
We’ll write :
一週間. イッシュウカンまえ . A week ago.

Another example. If we mean :
Two years ago.
We’ll write :
二年(). ニネン(カン)まえ . Two years ago.

Now if we mean :
In five days.
We’ll write :
五日間. カン. In five days.

Another example. If we mean :
In five months.
We’ll write :
. ゲツ. In five months.
So far, please note that as much as we use the kanji with its purely Japanese pronunciation まえ, as much we use the kanji in its Sino-Japanese pronunciation .

Now that we’ve seen all of this, we can take it even further. If we mean :
For a week.
If you think logically, you may have already guessed. We’ll write it this way :
一週間から . イッシュウカンまえから . For a week.
And so, to say :
Until in a week.
We’ll write :
一週間まで . イッシュウカンまで . Until in a week.

Good ! With everything we have just seen, you have plenty to have fun making sentences while learning to situate yourself in time and express duration. Don’t hesitate to revise the particle course から and まで to refresh your memory.

I will specify it again, all this, we’ll be able to use it with the suffix . and the prefix . ダイ to create ordinal numbers. I quickly give you some examples :
十四年. ジュウネン. The fourteenth year
十週. ジュウシュウ. The tenth week
二日. . The second day
三十日. サンジュッ. The thirtieth day
十一週. ジュウイチシュウ. The eleventh week

You remember that to express the duration in days, weeks and years, we use the suffix . カン to mean that we are talking about a duration. Now that we want to mean ordinal numbers for days, weeks, and months, we use the suffix .. Do not forget it !
To count the months in Japanese, be aware that there are two ways to do this. You can count the months using the suffix . attached to the Sino-Japanese pronunciation of kanji. Or you can count the months in purely Japanese. I will first give you some examples in Sino-Japanese with the suffix . and then, the same examples but in purely Japanese.

Sino-Japanese
. イッゲツ. The first month
. ゲツ. The second month
. サンゲツ. The third month
. よんゲツ. The fourth month
. ゲツ. The fifth month
. ロッゲツ. The sixth month
. ななゲツ, シチゲツ. The seventh month

Purely Japanese
一月 . ひとつき . The first month
二月 . ふたつき . The second month
三月 . みつき . The third month
四月 . よつき . The fourth month

As a general rule, after the fourth month, we stop counting in purely Japanese to continue in Sino-Japanese, but you can be simply counting the months only in Sino-Japanese with the suffix . as we saw earlier.

Units of measurement in mathematics

We can finally switch to other units of measurement that you are familiar with since you studied them in elementary school. These are the meter, the gram, the kilometer, the kilogram, the kilo... You will see, it will be super easy, the hardest part is now behind us.
I will start by showing you all of the above units of measurement below with examples in Japanese. In fact, as you will see, all the units of measurement that we are familiar with are either katakanized, or the Japanese use the international symbol specific to each unit of measurement :
Meter . メートル . m
Gram . グラム . g
Kilometer . キロメートル . km
Kilogram . キログラム . kg
Kilo . キロ . k
Degree . セ氏 .セシ . °C

I now give you some examples of use. If we want to write for example « twenty meters » or « fifty-five grams » or even « ten kilometers », « forty-four kilograms », « seven kilos », « twenty-two degree celsius », here is how we will write all of this :
20 meters . 20メートル . m
55 grams . 55グラム . g
10 kilometers . 10キロメートル . km
44 kilograms . 44キログラム . kg
7 kilos . 7キロ . k
22 degrees . セ氏22. セシ22. 22°C

What do we notice ? Well, in the way of writing meters, grams, kilometers, kilograms or kilos in typically Japanese, we write the number, most often in Arabic numerals (since we are here in the field of science) and the unit of measurement katakanized. We can also write the unit of measurement using the international symbol. The Japanese also do this very often. All this, we have seen it two paragraphs above.
Now let’s take a closer look at the degrees. To write degrees in typical Japanese, we have セ氏 . セシ which means « Celsius » and the kanji . to say « degree ».
Now let’s move up a gear (yes, I already said that above but hey !). If we mean « square meter » or « cubic meter ». Or if we mean « kilometer per hour » or « meter per second », « square meter per second »… how are we going to say all this in Japanese ? Well, that’s what we’ll see right away.
First, let’s see how we say in Japanese « square », « cube » and « each, every » (for example to say « meter per second ») :
平方 . ヘイホウ . Square
立方 .リッポウ . Cube
. マイ . Each, every, per
Before giving you the examples, one thing should be very clear. The word 平方 . ヘイホウ designates the square as an adjective, this word has absolutely nothing to do with the geometric shape of the same name in English.
That being said, I will now give you some examples, starting first with the units of measurement :

m2 . 平方 . メートル
To indicate an area, we write the word 平方 . ヘイホウ before the word メートル.

m3 . 立方 . メートル
To indicate a volume, we write the word 立方 . リッポウ before the word メートル.

km/h . キロメートル
To say « kilometer per hour », we first write the word キロメートル, first, and then to say « per hour », we use the word . マイ, which we have already seen in the course on « time complements » and which means « each, every, per » then the kanji in its Sino-Japanese pronunciation , which gives us . マイジ which means « per hour ».

m/s . メートル
To say « meter per second », we first write the word メートル, then to say « per second », we use the word . マイ, which we have already seen in the course on « time complements » and which means « each, every, per » then the kanji in its Sino-Japanese pronunciation ビョウ, which gives us . マイビョウ which means « per second ».

m2/s . 平方メートル
To say « square meter per second », we first write the word 平方 . ヘイホウ before the word メートル to indicate that we are talking about an area. Then to say « per second », we use the word . マイ, which means « each, every, per » then the kanji in its Sino-Japanese pronunciation ビョウ, which gives us . マイビョウ which means « per second ».

kg/m3 . キログラム平方メートル
To say « kilogram per cubic meter », we first write the word キロメートル. Then to say « per cubic meter », we use the word . マイ, which means « each, every, per », then we put before the word メートル the word 立方 . リッポウ to indicate that we are talking about a volume. So, 立方メートル . マイリッポウメートル means « per cubic meter ».

V x s . ボルト
Now if we want to multiply values, for example the magnetic induction flux, the Weber is calculated in volt seconds. Here we will just put the values one after the other. The volt, ボルト and the second, . ビョウ. There you go, nothing could be simpler.

T x m2 . テスラ平方メートル
The Weber can also be expressed in Tesla square meter. We therefore follow the same way as in the previous example. We place the elements one after the other. We first write テスラ, then we write the word 平方 . ヘイホウ before the word メートル.

m/s2 . メートル
Here we have a small special case. To say « meter per second squared », we cannot use the word 平方 . ヘイホウ to say « second squared ». We are not talking about an area because « second squared » means we multiply seconds by seconds. So, we write the word メートル, then we use the word . マイ, which means « each, every, per » then the kanji in its Sino-Japanese pronunciation ビョウ, which gives us . マイビョウ which means « per second ». We rewrite it a second time to express the idea that we are multiplying seconds by seconds. This is how we say « per second squared ».

kg x m/s2 . キログラムメートル
Okay, I think you’ve figured it out now so I’ll leave it to you for this last example.

Small details to know

Also know (afterwards, that’s the conclusion, I promise!) that, in everyday life, the Japanese use a different formulation for speeds. For example, if we mean 25 km/h, we can write it 時速25キロ(メートル).
Note that in Japanese, if the context can make us understand that we are talking about kilometer, we can perfectly say and write simply キロ instead of キロメートル, something we don’t do in English !
The word 時速 . ジソク is used as a prefix and introduces a length (here, km) to make it a speed expressed per hour. For minutes and seconds, just follow the same pattern : 分速 . フンソク and 秒速 . ビョウソク.
In the course, . マイジ is a relevant scientific writing because it can be applied to other units as seen with kg/m3, but on a daily basis, the Japanese prefer to use the expression 時速 . ジソク !
We have the same differentiation in English : « kilometer hour » is the current expression, « kilometer per hour » is the exact scientific expression !

I’ll end this part with, this time, an example sentence. If I mean :
The car travels at fifty kilometers per hour.
How am I going to say that ?
Okay, we know the word « car » (. くるま), we know how to say 50 km/h (時速50キロメートル).
The verb « to travel », to speak of a vehicle is said : 走行する . ソウコウする. It is a verb with する. The word 走行 . ソウコウ means « journey, driving a vehicle, a program or a job, traveling ». By adding the verb する which means « to do », depending on the context of the sentence, 走行する . ソウコウする can be translated in various ways. Here we are talking about a vehicle, so we will translate it by the verb « to travel ».
車は時速50キロメートル走行する。
The car travels at fifty kilometers per hour.

Note that we are using the particle of the means. Indeed, how does the car travel ? It travels at fifty kilometers an hour. It may sound quite bizarre in terms of wording but, in Japanese, when we mean a vehicle that travels at such speed, a person or an animal that walks or runs at such speed... in Japanese, this is the means so we use the particle of the means.
Remember that I briefly touched you on the verb する in the particle ’s course. Don’t worry, we’ll cover all of this in much more detail in the third season, which is all about verbs.
For now, when I give you する verbs like this from time to time, learn them as such, memorize the explanations I give you. You’ll see, it will be much easier later when we see all this more in detail when the time comes.

Conclusion

We have finally arrived at the end of this course on units of measurement in Japanese. Another particularly long course, I thought it would be shorter than the previous one, but in the end, its writing consumed a lot of my time. What a relief to have come to the end !
Everything that we have seen on units of measurement in mathematics will undoubtedly delight all those of you who are more scientific, who are interested in the Japanese language and who wonder how all these mathematical formulas are pronounced in Japanese, you are now served ! Of course, there are a lot of other math formulas that haven’t been covered in this course, but at least we’ve covered the whole topic of units of measure in Japanese.
Overall, the units of measurement that you will be most likely to use are rather the ones we saw at the very beginning: the units of measurement for counting floors, grades, episodes, number of times, occurrence… and the units of measure to express duration. Finally, even if you may not have a mind very focused on mathematical things, still make an effort to remember the few examples of mathematical formulas that I gave you in this course... you may find it useful one day, who knows ?
As you will understand, this course is very closely linked to the previous course on numeral classifiers and it is important, I repeat it one last time, to distinguish between the two. So take your time to reread this course as many times as needed, also reread the previous course. You probably won’t memorize all of the content on first reading, or second in my opinion, but it’s important that the numeral classifiers and units of measurement are clear in your mind before you move on.
This course is now over and I don’t know if you get bored of that same chorus but hey, as usual, thank you for reading it. Continue to work well, take a break if necessary and we meet for the next course.
Work well !