Expressing volition and desire with たい and ほしい

In this lesson, we're learning three ways we can express desire or intent in Japanese.

The "volitional" form, おう/よう, says that you want to or will do something, or invites volition in other people like "let's X". It's also used in compound constructions about volitional action. The volitional form of godan verbs is -ou, and the volitional form of ichidan verbs is よう. It's pronounced with a "long o", not お plus う.

行こう
Let's head out.

行こうか
How about we go?

食べようと思う
I think I'll eat.

Note: we will learn this usage of と with 思う in a later section, don’t worry too much about it now.

The volitional form of です is でしょう and of だ is だろう. These usually "invite an idea", like conjecture or possibility.

いいでしょう
It's good, don't you think? 

犬だろうと、猫だろうと、なんでも問題ありません   
Perhaps dogs, perhaps cats; whichever it is, there’s no problem. 

The second way to express desire is たい. たい is an い-adjective-like auxiliary that attaches the same way as ます.

死にたい
I want to die.

アイスが食べたい
I want to eat ice cream.

In the last example sentence, を is acceptable too. In respect to が and を, たい works similarly to potential verbs. Either が or を can be used to mark the object/target of desire, although different verbs may have specific preferences about one or the other. Don’t try to memorize this, just know it exists and is valid Japanese.

The last way to express wanting is with 欲しい, an い-adjective.

アイスがほしい
I want ice cream

Note: Similarly to たい, ほしい also falls into the category of quirky adjectives where が marks the object of desire, and can sometimes be replaced with を. However, unlike with たい, をほしい is very much less proper and less common. You might still see it, but a lot of people will consider it awkward Japanese. It’s best to avoid using it.

Another quirk of ほしい is that it can be used as auxiliary after the て form of a verb to issue soft commands or requests.

その話はやめてほしい
I want you to stop talking about that

It can sound a bit more impersonal and indirect than てください, and it can also be used to provide general advice about what you’d like someone to do from your point of view. The important thing to remember is that you use がほしい to talk about yourself, and てほしい to talk about others.