[Purpose of going: go to do ~]
Connection: Verb stem (masu-stem) + に + 行く/来る/帰る
How to form the verb stem:
- Group 2: 食べる → 食べ → 食べに行く (go to eat)
- Group 1: 買う → 買い → 買いに行く (go to buy); 泳ぐ → 泳ぎ → 泳ぎに行く (go to swim)
- Irregular: する → し → しに行く (go to do); Noun + し → 買い物しに行く (go shopping)
With different movement verbs:
- に行く (go to do): 映画を見に行く (go to see a movie)
- に来る (come to do): 遊びに来てください (please come visit/hang out)
- に帰る (go home to do): 荷物を取りに帰る (go home to get luggage)
Note: The purpose verb is in STEM form (not dictionary form). This is different from noun + に行く.
- 映画を見に行く (go to watch a movie — verb stem)
- 映画に行く (go to a movie — noun)
Examples:
- 昼ごはんを食べに行きましょう (Let's go eat lunch)
- 友達に会いに行きます (I'm going to see my friend)
- 何をしに来ましたか (What did you come to do?)