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！
（6)現(xiàn)在完成時(shí)表示一個(gè)發(fā)生在過去的、對(duì)現(xiàn)在仍有影響的動(dòng)作，或表示開始在過去，并且一直延續(xù)到現(xiàn)在，甚至還可能延續(xù)下去的動(dòng)作。
①在完成時(shí)由“助動(dòng)詞have（has)+動(dòng)詞的過去分詞”構(gòu)成。
②表示發(fā)生在過去的對(duì)現(xiàn)在仍有影響的動(dòng)作時(shí)，時(shí)間狀語有：already,yet,just,once,twice，ever,never,three times,before等。如：I have never seen such fine pictures before.（我以前從來沒有看過這么好的畫)/He has just gone to England.（他剛?cè)ビ?
③表示在過去開始一直延續(xù)到現(xiàn)在（可能延續(xù)下去)的動(dòng)作或狀態(tài)時(shí)，時(shí)間狀語有：for（two years),since 1990,since（two weeks ago)和since引導(dǎo)的狀語從句。如：I have been away from my hometown for thirty years.（我離開家鄉(xiāng)有30年了)/Uncle Wang has worked in the factory since it opened.（自從這家工廠開張，王叔叔一直在那兒工作)
④口語中have got往往表示have（有)的意思。如：They have got thousands of books in their library.（他們圖書館有上萬本書)
⑤have been to與have gone to的區(qū)別：have gone to（“已經(jīng)去了”)表示人不在這里，have been to（“去過”)表示人在這里。如：——Where is Mr Li？ –He has gone to the UK.（李先生在哪里？他去了英國。)/——Do you know something about Beijing？ –Yes,I have been to Beijing three times.（你知道北京的情況嗎？是的，我去過那里三次。)
⑥在完成時(shí)中，一個(gè)瞬間性動(dòng)詞（一次性動(dòng)作)不能與表示一段時(shí)間的狀語連用，此時(shí)須將該瞬間動(dòng)詞改為延續(xù)性動(dòng)詞或狀態(tài)動(dòng)詞。具體變化見下表：
|
瞬間性動(dòng)詞的完成時(shí) |
→ |
延續(xù)性動(dòng)詞或狀態(tài)動(dòng)詞的完成時(shí) | ||||
|
have |
(already) |
gone to… |
have |
been in / at … |
for (two years) | |
|
has |
|
come to… |
has |
been here |
since (1990) | |
|
(had) |
|
left… |
(had) |
been away from… |
| |
|
|
|
arrived… |
|
been in… |
| |
|
|
|
died |
|
been dead |
| |
|
|
|
begun |
|
been on |
| |
|
|
|
ended |
|
been over |
| |
|
|
|
bought... |
|
had… |
| |
|
|
|
borrowed… |
|
kept… |
| |
|
|
|
joined… |
|
been in … |
| |
或者使用下面這個(gè)句型：
It is /has been+（多久)+since+主語（人)+謂語（過去時(shí))+……+過去時(shí)間狀語
[注意] 在其它的時(shí)態(tài)中也存在類似問題，記住，關(guān)鍵是：瞬間動(dòng)詞不能和表達(dá)一段時(shí)間的狀語連用。如：How long may I keep the book？（這本書我能借多久？)（句子中keep取代了borrow)
