Japatan
Formação
- Vて形 + くる
- Vて形 + いく
- いA（〜く）+ なって くる・いく
- なA / N + に + なって くる・いく
Explicação
There are two main uses. (1) Change over time: 〜てきた shows a change that has gradually happened up to now (or something that has just started, like rain), and 〜ていく shows a change that will continue from now on. (2) Direction of movement: 買ってくる means go, buy, and come back; 持っていく means take something with you as you leave.
Exemplos
日本に 来て 一年。日本語が だんだん わかって きました。
It's been a year since I came to Japan. I've gradually come to understand Japanese.
これから もっと 寒く なって いくでしょう。
It will probably keep getting colder from now on.
ちょっと コンビニで 飲み物を 買って きます。
I'll just go buy some drinks at the convenience store (and come back).
明日の パーティーには ケーキを 持って いきます。
I'll bring a cake to tomorrow's party.
Observações
行ってきます, said when leaving, literally means "I'll go and come back." In the change use, words like だんだん and これから often appear together.
Gramática relacionada
Miniquiz
1あ、雨が 降って（ ）。傘を 持って いきましょう。
Resposta e explicação
Resposta: 1 きました
降ってきました means it has started raining. The sentence means "Oh, it's started raining. Let's take umbrellas."
2これからも 毎日 日本語を 勉強して（ ）つもりです。
Resposta e explicação
Resposta: 3 いく
これからも points to the future, so 〜ていく (continuing from now on) fits. The sentence means "I intend to keep studying Japanese every day from now on."
3ちょっと 郵便局へ 行って（ ）。すぐ 戻ります。
Resposta e explicação
Resposta: 3 きます
The speaker will go and come back, so 行ってきます is correct. The sentence means "I'm just going to the post office. I'll be right back."
