~に行く
Go somewhere to do something
You’ll be able to say you’re going somewhere for a specific purpose or activity.

図書館へ本を借りに行きます。
toshokan e hon o kari ni ikimasu.
What do you think this sentence means?
I’m going to the library to borrow a book.
Go somewhere for the purpose of doing something
Use a verb stem + に with a movement verb to say that you go, come, or return somewhere in order to do that action.
友達と映画を見に行きます。
tomodachi to eiga o mi ni ikimasu.
I am going to see a movie with a friend.
Verb stem + に + movement verb
Use the ます-stem without ます, add に, then use 行く, 来る, or 帰る.
昼ご飯を食べに行きます。
hirugohan o tabe ni ikimasu.
I am going to eat lunch.
友達が遊びに来ます。
tomodachi ga asobi ni kimasu.
A friend is coming to hang out.
家に荷物を取りに帰りました。
ie ni nimotsu o tori ni kaerimashita.
I went back home to get my bag.
The destination can appear too
When needed, state the destination with に or へ before the purpose phrase.
図書館に本を借りに行きます。
toshokan ni hon o kari ni ikimasu.
I am going to the library to borrow a book.
駅へ友達を迎えに行きます。
eki e tomodachi o mukae ni ikimasu.
I am going to the station to meet my friend.
日本に勉強しに来ました。
nihon ni benkyou shi ni kimashita.
I came to Japan to study.
に for a destination vs に for a purpose
After a place, に says where you are going. After a verb stem, the same に says what you are going to do there.
に, what for
昼ご飯を食べに行きます。
hirugohan o tabe ni ikimasu.
I am going to eat lunch.
食べ is a verb stem, so に gives the purpose.
に, where to
学校に行きます。
gakkou ni ikimasu.
I go to school.
学校 is a place, so に gives the destination.
昼休みにコンビニへお茶を買いに行きます。
hiruyasumi ni konbini e ocha o kai ni ikimasu.
I go to the convenience store to buy tea during lunch break.
日曜日に友達と映画を見に行きます。
nichiyoubi ni tomodachi to eiga o mi ni ikimasu.
I'm going to see a movie with a friend on Sunday.
母はスーパーへ野菜を買いに行きます。
haha wa suupaa e yasai o kai ni ikimasu.
My mother is going to the supermarket to buy vegetables.
11 more examples in the grammar path — free for a limited time.