Movement towards action refers to sentences like the following:
I am going to eat.
I am coming to meet her.
I went to watch a football game.
In Japanese we use the following structure. Note that this applies to all three main verbs of motion: to go, to come, and to return.
【Verb: Stem】に【行く】or【来る】or【帰る】
To go / come / return to do something
会いに来ます。
To come and meet.
明日は、銀座に寿司を食べに行きます。
Tomorrow I’m going to go and eat sushi in Ginza.
遊びに来ませんか?
Won’t you come and hang out.
サッカーの試合を見に行きました。
I went to watch a football game.
昼ご飯を食べに帰ります。
I will go home to eat lunch.
Using Action Nouns
You do not always have to use a verb stem. For “suru-verbs” (verbs made of a noun + する, such as 勉強する or 買い物する), you can drop the する entirely and attach に directly to the action noun.
買い物に行きます。
I will go shopping.
日本へ旅行に来ました。
I came to Japan to travel.
The Particle Trap (で vs に)
It is easy to slip up on the grammar here regarding locations. You might think that to say “I will go to study in the library” the grammar should be…
図書館で勉強しに行きます。(✘)
I will go to study in the library.
… because the library is the place of action and the following, as we have seen, is correct:
図書館で勉強します。
I will study in the library.
However, when we want to express movement towards an action, it is the final verb—“to go” or “to come”—which dictates the particle. Because you are traveling to a destination, we must use に or へ.
図書館に勉強しに行きます。
I will go to study in the library.
We also need to be careful when using the directional particle へ (he).
東京駅へ行きます。(✔)
東京駅に行きます。(✔)
I will go to Tokyo station.
That’s fine. But the directional particle cannot be used to mark the purpose of the action. Only に can be used for the purpose.