Translation guide
The English word 'month' refers to a unit of time roughly corresponding to one cycle of the moon's phases. In Japanese, the most common equivalent is 月 (つき / がつ), but its usage depends on context: naming specific months, counting months, or referring to a month in general.
The learner wants to say the name of a month, like 'January' or 'March'.
Japanese month names are formed by the number of the month plus 月 (がつ). January is 1月 (いちがつ), February is 2月 (にがつ), and so on.
My birthday is in March.
August is very hot.
The learner wants to express a period of time measured in months, like 'for three months' or 'two months ago'.
Use the counter か月 (かげつ) after a number to count months of duration. Note the reading changes for 1 month (いっかげつ), 6 months (ろっかげつ), 8 months (はっかげつ), and 10 months (じゅっかげつ or じっかげつ).
I studied Japanese for three months.
I watch a movie once a month.
Adding 間 (かん) emphasizes the duration. It is often optional but can make the meaning clearer.
He was in Japan for six months.
The learner wants to talk about a month in a relative sense, like 'this month' or 'last month'.
Means 'this month'. The reading is こんげつ, not いまつき.
I'm busy this month.
Means 'next month'.
Means 'last month'.
Means 'every month'. Both readings are common, but まいつき is slightly more frequent.
I buy a magazine every month.
The learner wants to refer to the moon itself, not the time unit. This is a different meaning of 'month' that is archaic in English but related.
The Japanese word for 'moon' is 月 (つき). This is not used for the time unit 'month' except in some poetic or compound contexts. Do not confuse with がつ or げつ.
The moon is beautiful tonight.
The kanji 月 can be read as つき (moon), がつ (month name), or げつ (month counter). Using the wrong reading can cause confusion. For example, 一月 (いちがつ) means January, while 一か月 (いっかげつ) means one month duration.
January is one month.
When counting months, always use か月 (かげつ) with the number. Using just 月 after a number would be interpreted as a month name (e.g., 3月 = March, not three months).
I waited for three months.
Please come in March.
来月日本へ行きます。
I'm going to Japan next month.
先月新しい車を買いました。
I bought a new car last month.