～う／よう
let’s / I’ll (volitional)
The volitional form (～う／よう) expresses the speaker's intention or will, usually as a suggestion to do something together, or a decision to do something yourself. It is the form used in 行こう, 食べよう and しよう, and its polite version is ～ましょう.
In English it corresponds to “let's ...” when aimed at others, and “I'll ... / I think I'll ...” when the speaker is talking about their own plans.
1. Suggesting to do something together
On its own at the end of a sentence, the volitional is a casual “let's”.
一緒に昼ご飯を食べよう。
“Let's have lunch together.”
- 一緒に（いっしょに）= together
- 昼ご飯（ひるごはん）= lunch
- を = object marker
- 食べよう（たべよう）= let's eat
2. Announcing your own resolve
Followed by と思う (“I think”), the volitional expresses your own intention: “I think I'll ...”. Here it is not an invitation at all.
来年、日本に行こうと思う。
“I think I'll go to Japan next year.”
- 来年（らいねん）= next year
- 日本（にほん）= Japan
- に = destination marker
- 行こう（いこう）= I'll go (volitional)
- と = quotation particle
- 思う（おもう）= to think
3. Polite ～ましょう and ～ましょうか
The polite volitional is ～ましょう (“let's”). Adding か turns it into a gentle invitation or offer: ～ましょうか = “shall we ...?”.
そろそろ帰りましょうか。
“Shall we head home soon?”
- そろそろ = soon / about time to
- 帰りましょうか（かえりましょうか）= shall we go home?
How to form it
Godan (u-verbs): change the final u-sound to the o-row and add う. Ichidan (ru-verbs): drop る and add よう. Irregular verbs have their own forms, and polite ～ます becomes ～ましょう.
- 行く（いく）= to go → 行こう（いこう）= let's go
- 飲む（のむ）= to drink → 飲もう（のもう）= let's drink
- 食べる（たべる）= to eat → 食べよう（たべよう）= let's eat
- 見る（みる）= to see → 見よう（みよう）= let's watch
- する = to do → しよう = let's do
- 来る（くる）= to come → 来よう（こよう）= let's come
- 行きます（いきます）= to go (polite) → 行きましょう（いきましょう）= let's go
Key idea
The volitional is will pointed at an action. Aimed at others it means “let's”, aimed at yourself (often with と思う) it means “I'll”.
Other N4 grammar
Updated .