OH, let's just do it together (Unit 4)
The volitional form has a unique combination pattern:
Before we get into that, let's talk about what is meant by "volitional," a word that I've always found a bit confusing. The word "volition" means "the power to make your own choices." In Japanese, "the volitional form" is called 意志形 (いしけい). 意志 (いし) means "will" (in the sense of "willpower" or "strength of will," for example). Thus, 意志形 is literally the "will-form." It is used in a few different ways:
(1) When saying let's (choose to) do something.
(2) When saying I think I'll (choose to) do something.
(3) Embedded into a few more complicated grammar patterns we'll see in the future.
Take the verb 行く (いく // to go). Put it into volitional form, and you get 行こう (いこう // let's go). Put it in a sentence, and you might get:
早く行こう。
はやく いこう。
Come on, let's go.
Literally: "quickly /early + let's go."
Remember when we saw the following sentence?
一緒に座らない？
いっしょ に すわらない？
Do you wanna sit together?
Literally: “together + に + won't sit?”
Compare that to this sentence:
一緒に座ろう。
いっしょ に すわろう。
Let's sit together.
Literally: "together + に + let's sit."
What's going on with our godan verbs in the sentences above? Well, we're changing the final "-u" sound to an "-o" sound, then adding an extra ～ う, effectively lengthening the sound of the "o."
行く → 行こ- → 行こう
いく → いこ- → いこう
座る → 座ろ- → 座ろう
すわる → すわろ- → すわろう
As you might have guessed by now — or inferred simply by looking at the chart at the top of this lecture — ichidan verbs are a bit different.
The stem is unchanged. Then we add ～ よう.
食べる →食べ- → 食べよう
たべる →たべ- → たべよう
Let's say that you and I went to a restaurant and ordered a ton of food. Looking down at all of the plates laid out before us, you could turn to me and say:
全部食べよう！
ぜんぶ たべよう！
Let's eat all of it!
Literally: "everything / all + let's eat!"
Or maybe you are at home by yourself, eating ice cream out of the carton. A strange force takes hold of you, and you find it is getting harder and harder to put down the spoon. After a considerable amount of mental struggling, you finally think to yourself:
全部食べよう！
ぜんぶ たべよう！
I'm gonna eat all of it!
Literally: "everything / all + let's eat!"
This is one example of how the exact same sentence can have considerably different translations depending on the context in which it appears.
For Group III verbs, you guessed it, you should just memorize them:
する → しよう
来る (くる)→ 来よう (こよう)