ago和before的區(qū)別

　?、? ago adv. 以前指從此刻起，若干時間以前，通常與過去連用。如：

　?、?It happened two days ago.這件事發(fā)生在兩天以前。

　?、?I met him a few minutes ago.我在幾分鐘以前碰到他。

　?、? before adv, prep conj 以前指從那時起若干時間以前。通常與完成時、過去時等連用。還可用作前置詞或連接詞表時間，而ago 則不能這樣用。

　?、?He said that he had seen her two days before.他說他兩天前見到過她。(表從她說話那時起兩天前)

　?、?I had been fine the day before.(那天)前一天的天氣很好。

　?、?Ive seen that film before.

　?、?I never met him before.