ようではないか

ようではないか follows the volitional form of a verb and calls on a group to act together: "let us…", "come on, let's…". It sounds like a speech, an editorial or a leader rousing a team, and it is stronger than the plain volitional. In speech it is shortened to ようじゃないか.

The verb is in the volitional form, so a う-verb ends in おう and a る-verb in よう: がんばろう頑張ろう, かんがえよう考えよう, しよう, こよう来よう.

• × 頑張るではないか → 頑張ろうではないか

ようではないか, ましょう and the plain volitional

ましょう and the plain volitional make an ordinary suggestion. ようではないか rallies people toward a shared goal, so on an everyday proposal it sounds pompous: for "let's have lunch" you say ひるごはん昼ご飯をたべましょう食べましょう or たべよう食べよう.

Usage notes

These go beyond calling a group to act.

Taking up a challenge

With a verb of doing and てやる, ようじゃないか accepts a challenge or a provocation: "fine, I'll do it".

ではないか without the volitional

After anything other than a volitional, ではないか is a different pattern: "isn't it?", "surely". いいではないか is "that's fine, isn't it?", not a call to action.