Learn German: Es kommt darauf an, wie viel Zeit wir haben. - It depends on how much time we have.

In German, the verb phrase for 'to depend on' is ankommen auf. When 'on' points to a whole action or idea that follows, like how much time we have, German uses a da-word like darauf as a bridge. It literally means 'It depends on it'.

Is the main verb kommen? What is an doing there?

The main verb is actually ankommen, a separable verb. In a standard main clause like the first half of this sentence, the prefix an detaches and moves to the end of that clause.

Why is the verb haben at the very end of the sentence?

The second part of the sentence, wie viel Zeit wir haben, is an indirect question. Indirect questions act as subordinate clauses in German, which means the conjugated verb (haben) gets kicked to the very end of the clause.

Why is it wie viel instead of wie viele?

You use wie viel (how much) for uncountable nouns like Zeit (time) or money. If you were talking about countable nouns, like hours (Stunden) or days (Tage), you would use wie viele (how many).