How to ask "Do you want to be ...?" question?

Question

I'm going through my elementary Japanese learning book and another question came to mind.

So, 欲しい｛ほしい｝ means "want" and 居る{いる} means "to be", "to have" or "to exist"

How does one combine the two to say "Do you want to be ...?"

Example:

Do you want to be my team member (e.g sports team member) ?

I first thought:

僕のチームのメンバーが欲しいですか。

But that sounds more like "Do you want my team member?"

Then my next thought was:

僕のチームのメンバーがいますか。

However, doesn't that mean "Does my team member exist?"

:D

So...yeah, scratching my head at the moment.

Answer 1

Translating "want" is slightly difficult:

• "want that" =「thatが欲しい」"want to own that stuff"
• "want to do that act" = 「thatをしたい」
• "want to be that" = 「thatになりたい」"want to become that role/position/status" or「thatでありたい」"want to keep that state"

I think「僕のチームのメンバーになりたいですか」is good for "Do you want to become my team member?". If you ask him/her to become your team member, you can also say「僕のチームのメンバーになりませんか」.

「僕のteam memberがいますか」means "Does my team member exist?" as you say.

Answer 2

Basically, 欲しい is used only when:

• the subject wants some thing (e.g., "水が欲しい": "I want [some] water")
• after the て-form of a verb, when the subject wants somebody else to do something (e.g., "やめてほしい": "I want [you] to stop [doing that]")

In your example though, it's not a matter of the subject --"you"-- wanting something to happen, but a question of what the other person wants. In that case, you could use the continuative form of the verb (連用形{れんようけい}) + -たい:

僕のチームのメンバーになりたい(ですか・かな)?

However, keep in mind that using -たい in the 2nd person like this is considered to be an informal construction, usually best reserved for friends and/or people (significantly) younger than you are.

In a polite setting, asking what somebody wants is usually avoided simply by asking directly what that person will do:

僕のチームのメンバーになりませんか?