i've been here before 这句是什么语法啊?

这句话是什么时态It feels like I've been here before I believe we‘ve met before.-No,.I’ve never been here before. I'Ve Been Here 歌词 i've never been here I've been here for three months的同义句 I've never been here 什么意思 I've been there before 还是I've been to there before? 现在完成时态的 I've been skating for five hours 这句是什么时态,与I've skate o,i have been here before是什么意思 i've never been here before,so it's all s_____ to me以s开头 填什么 i've been ...是什么时态? I've been working here for seven years.(改为同义句）