～ていく
go on doing / motion away
～ていく is made by taking the て-form of a verb and adding いく（行く, to go）. Literally it means “do something and go”, and it also describes changes that continue away into the future. It is the mirror image of ～てくる.
In English it maps to expressions like “take (along)”, “go on doing”, or “will keep getting”.
1. Doing something and going / taking along
Use ～ていく when someone does an action and then moves away from where the speaker is, often when carrying something with you.
お弁当を持っていきます。
“I’ll take a boxed lunch with me.”
- お弁当（おべんとう）= boxed lunch
- を = object marker
- 持っていきます（もっていきます）= will take (along)
2. A change continuing into the future
～ていく also describes a change that starts from the present and keeps going from now on.
これから寒くなっていく。
“It will gradually get colder from now on.”
- これから = from now on
- 寒く（さむく）= cold (adverb form of 寒い)
- なっていく = will go on becoming
Compare: 寒くなってきた looks back at the change up to now, while 寒くなっていく looks forward at the change still to come.
How to form it
Verb て-form + いく
- 持つ（もつ）= to hold → 持っていく（もっていく）= take along
- なる = to become → なっていく = go on becoming
- 変わる（かわる）= to change → 変わっていく（かわっていく）= keep changing
Key idea
～ていく points away from the speaker, away in space (someone leaves with something) or forward in time (a change moves on into the future).
Built on the same stem
Updated .