2015年職稱英語考試已經(jīng)開始備考，本階段應(yīng)該多整理一些基礎(chǔ)詞匯和語法。為此，醫(yī)學(xué)全在線職稱外語頻道特整理了“2015年職稱英語備考語法資料”供您參考，希望對(duì)您有幫助！
（7)過去完成時(shí)表示過去某一時(shí)間或某一動(dòng)作發(fā)生之前已經(jīng)完成的動(dòng)作。簡言之,過去完成時(shí)所表示的時(shí)間是“過去的過去”。
①過去完成時(shí)由“助動(dòng)詞had+動(dòng)詞的過去分詞”構(gòu)成。
②過去完成時(shí)時(shí)間狀語有：by（yesterday),by then,by the end of（last…)或者由when，before等引出狀語從句。有時(shí)句子中會(huì)有already,just,once,ever,never等詞語，也會(huì)有for… 或since…構(gòu)成的時(shí)間狀語。如：They had already finished cleaning the classroom when their teacher came.（當(dāng)老師來的時(shí)候他們已經(jīng)打掃完了教室)/ The woman had left before he realized she was a cheat.（在他發(fā)覺那個(gè)婦女是個(gè)騙子時(shí)她已經(jīng)走掉了)
③過去完成時(shí)常用于賓語從句中、after引導(dǎo)的從句中，或者從句是before引導(dǎo)的主句中。如：After I had put on my shoes and hat,I walked into the darkness.（我穿上鞋子戴上帽子走進(jìn)了黑暗之中)/ He said that he had never seen a kangaroo before.（他說他以前從來沒有見過袋鼠)
