に

The particle に serves as a marker for location, time, direction, and purpose. It is used to specify the goal of an action or describe where or when something happens.

• Location of existence

  Marks the location where something or someone exists (commonly used with いる or ある).

  つくえ机のうえ上にほん本があります。

  There is a book on the desk.

• Direction or destination

  Indicates the goal of an action (used with verbs like いく行く, くる来る, かえる帰る).

  こうえん公園にいきます行きます。

  I go to the park.

• Point in time

  Specifies the exact time when an action takes place.

  あす明日いちれいじ10時にしゅっぱつ出発します。

  I will depart at 10 o’clock tomorrow.
  Note: Not used with relative time expressions like きょう今日 (today), あす明日 (tomorrow), or いま今 (now).

• Recipient of an action

  Marks the indirect object or the recipient of an action.

  せんせい先生にしつもん質問しました。

  I asked the teacher a question.

• Purpose

  Indicates the purpose or intent of an action.

  えいが映画をみにいきます見に行きます。

  I am going to see a movie.

• Target of change or result

  Marks the result of a change or transformation.

  かれ彼はいしゃ医者になりました。

  He became a doctor.