一般過去時現(xiàn)在完成時主要用于：
1 、表示到現(xiàn)在為止這一時期中發(fā)生的動作或情況，即多次動作的總和。
e.g. We have learnt four English songs this month.
How many times have you read the novel?
For many days we haven`t seen each other.
2 、表示對現(xiàn)在有影響的某一已發(fā)生的動作。
e.g. The delegation has left 代表團已經(jīng)走了(說明現(xiàn)在不在這里)
Look, what you have done. 看你干的事。
與這一時態(tài)連用的時間狀語有：
already, yet, just, ever, never, by now, so far, recently, by the end of this month, since, for 短語，連詞 since 引導(dǎo)的時間狀語從句。
一般過去時與現(xiàn)在完成時的區(qū)別：
一般過去時：重在說明動作在過去發(fā)生時的具體情況(時間、地點、方式、對象、細節(jié)等)。
現(xiàn)在完成時：只提起已發(fā)生的動作(事實)及其影響，不說明動作發(fā)生時的具體情況。
cf. Have you had your lunch?
What did you have for lunch?
I have ever been to the Great Wall,_and_I went there last summer with my father.
注：現(xiàn)在完成時表達的動作常具有反復(fù)性，故下面一句是錯的：
Have you seen the six thirty`s news program?
應(yīng)改為：
Did you see the six thirty`s news program?
