What the heck is This?

[kentaku_sama]

So I've done genki for a while and I can't really understand why this is used in this context:

ブラジルに行ったことがありますか？　　
　　Response:　　メキシコならいｋったことがありますが、　ブラジルに行ったことがありません。

　Why　say that instead of : ブラジルにいった？　Or　ブラジルに行きましたか？　

And what in the heck is が　doing at the end of after a verb. Is it stating that that clause is a subject or what?

Someone plz explain these forms to me.

[furrykef]

Xことがありますか = Have you ever Xed?

が at the end of a sentence -- that is, after a verb -- means "but" (or sometimes something more like "and").

Q: Have you ever gone to Brazil?
A: I've been to Mexico, but I haven't been to Brazil.

If instead the question were ブラジルに行きましたか？, then it would mean, "Did you go to Brazil?" -- similar, but not the same and will sound unnatural if the other question is intended.

- Kef

[kentaku_sama]

Ariagtou wakatta