ago和before的区别

　　Ⅰ. ago adv. 以前指从此刻起，若干时间以前，通常与过去连用。如：

　　① It happened two days ago.这件事发生在两天以前。

　　② I met him a few minutes ago.我在几分钟以前碰到他。

　　Ⅱ. before adv, prep conj 以前指从那时起若干时间以前。通常与完成时、过去时等连用。还可用作前置词或连接词表时间，而ago 则不能这样用。

　　① He said that he had seen her two days before.他说他两天前见到过她。(表从她说话那时起两天前)

　　② I had been fine the day before.(那天)前一天的天气很好。

　　③ Ive seen that film before.

　　④ I never met him before.