二、用法：

　　have加過去分詞表示動(dòng)作發(fā)生在過去對(duì)現(xiàn)在的影響

　　had加過去分詞是指過去某一動(dòng)作之前已經(jīng)發(fā)生或完成的動(dòng)作，即動(dòng)作有先后關(guān)系，動(dòng)作在前的用過去完成時(shí)，在后的用一般過去時(shí)。

　　三、常用時(shí)間狀語(yǔ)：

　　have加過去分詞

　　1、表示到現(xiàn)在為止：already ,yet ,just ,ever, never ,before ,since ,so far, until now ,by now ,up to now.

　　2、表示最近：recentl,lately in the past/last few years

　　3、包含現(xiàn)在在內(nèi)的時(shí)間狀語(yǔ)：this morning/afternoon,all the  year ,all day

　　had加過去分詞

　　分兩種情況：

　　由時(shí)間狀語(yǔ)來判定

　　與過去完成時(shí)連用的時(shí)間狀語(yǔ)有：

　　1、如：I had finished reading the novel by nine o'clock last night.

　　2、如：We had learned over two thousand English words by the end of last term.

　　3、 before + 過去的時(shí)間點(diǎn)。

　　如：They had planted six hundred trees before last Wednesday

　　由“過去的過去”來判定。

　　1、當(dāng)賓語(yǔ)從句的主句為一般過去時(shí)，且從句的動(dòng)作先于主句的動(dòng)作時(shí)，從句要用過去完成時(shí)。在told, said, knew, heard, thought等動(dòng)詞后的賓語(yǔ)從句。

　　如：She said that she had seen the film before.

　　2、狀語(yǔ)從句中

　　在時(shí)間、條件、原因、方式等狀語(yǔ)從句中，主、從句的動(dòng)作發(fā)生有先后關(guān)系，動(dòng)作在前的，要用過去完成時(shí)，動(dòng)作在后的要用一般過去時(shí)。

　　如：After he had finished his homework, he went to bed.

　　注意： before, after 引導(dǎo)的時(shí)間狀語(yǔ)從句中，由于 before 和 after 本身已表達(dá)了動(dòng)作的先后關(guān)系，若主、從句表示的動(dòng)作緊密相連，則主、從句都用一般過去時(shí)。

　　如：After he closed the door, he left the classroom.

　　3、表示意向的動(dòng)詞，如hope, wish, expect, think, intend, mean, suppose等，用過去完成時(shí)表示"原本…，未能…"

　　如：We had hoped that you would come, but you didn't.