~ていく (2) (ongoing change)
Meaning
An auxiliary verb construction where いく follows the て form of a verb to express that an action or state continues to change or progress from the present into the future. It describes a gradual, ongoing shift moving forward in time.
This temporal use of ていく expresses that a change or trend will continue developing from now onward. The speaker observes a current state and projects that the change will keep going into the future. Common examples include populations decreasing, technology advancing, or seasons changing. This contrasts with てくる in its temporal sense, which describes changes that have been progressing up to the present moment. ていく looks forward; てくる looks back. The pattern works with both change-of-state verbs (増える, 減る, 変わる) and action verbs viewed as ongoing processes. Learners sometimes struggle to distinguish the directional and temporal uses; context usually makes it clear — if no physical movement is involved, the temporal reading applies.
Examples
- これから気温が下がっていくでしょう。 The temperature will probably keep dropping from now on.
- 日本語を続けて勉強していくつもりです。 I intend to keep studying Japanese.
- この町の人口は減っていくだろう。 The population of this town will probably keep declining.
Usage Guide
Context: spoken, written, everyday
Tone: reflective
Do Say
- これからも日本語を頑張っていきます。
- 環境問題はますます深刻になっていくだろう。
- 少しずつ慣れていくと思います。
Don't Say
- だんだん暖かくなってきた。(Using てくる when describing a future-oriented trend — てくる looks backward to the present, not forward) → これからだんだん暖かくなっていくだろう。
- 最近物価が上がっていく。(Using ていく for a change already observed up to now — use てきた for past-to-present change) → 最近物価が上がってきた。
Origin & History
The temporal extension of いく derives from its core meaning of forward movement. The metaphorical mapping from physical space to time — 'going forward' meaning 'continuing into the future' — is a natural semantic development shared by many languages.
Cultural Context
Generation: All ages
Social background: Universal
Related Phrases
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