怎么区分 i have seen him 和 i had seen him 最好给下具体的翻译 我真是理解不上去这两个.

I have seen him yesterday. I saw him this morning.与I have seen him this morning 怎么翻译,区别 Never have I seen him before和Never before have I seen him 是一 never have I seen him before.never before have I seen him .哪 i never saw him和i have never seen him有什么区别? I have been here since I was born 和I haden't seen him since i was to have seen him last week I have never seen him look so well before. This is the first time I have seen him. I have seen him somewhere.( 改为否定句) it is three years since i have seen him ____he____(come)yesterday,I would have seen him.