A1
に — where to, when, and where something is
The main uses of に in Japanese — destination, point in time, existence, and the receiver of an action — and how it differs from で.
に does several jobs, and they share one idea: a point. A point in space you are heading to, a point in time, a point where something sits.
Destination
学校に行きます。
Gakkō ni ikimasu.
I go to school.
へ also marks direction and is slightly softer — more towards than to. With a plain destination the two are interchangeable, and に is more common.
A point in time
七時に起きます。
Shichi-ji ni okimasu.
I get up at seven.
Only for times you could put on a clock or a calendar. Relative times — 今日, 明日, 来週 — take no particle at all, which is the mistake worth knowing in advance.
明日に行きます。
明日行きます。
明日 is relative to now, so it takes no に. Absolute times do: 月曜日に, 三時に, 2026年に.
Where something exists
With あります and います, に marks the place.
部屋に猫がいます。
Heya ni neko ga imasu.
There’s a cat in the room.
The receiver
Whoever gets something, is told something, or is met.
友達に電話します。
Tomodachi ni denwa shimasu.
I’ll phone my friend.
母に手紙を書きます。
Haha ni tegami o kakimasu.
I’ll write my mother a letter.
に against で
This is the distinction to get straight, and it is not about the place — it is about what the sentence is doing with it. に marks where something is; で marks where something happens. See で.
図書館にいます。
Toshokan ni imasu.
I’m in the library.
図書館で勉強します。
Toshokan de benkyō shimasu.
I study in the library.
Same library. The first is location, the second is the setting of an activity.