i haven't seen it before.这句话对吗?

i haven't seen it before.这句话对吗?
i haven't seen it before.这句话对吗?

i haven't seen it before.这句话对吗?
对的,表示我之前还没有见过它
现在完成时的否定形式!

对的，现在完成时

对

i haven't seen it 的意思是到目前为至还没有看到。而加上before就有点前后矛盾。如果一定要表达，就应用过去时，即：I didn't see it before.