概念：经常、反复发生的动作或行为及现在的某种状况。

时间状语：

always, usually, often, sometimes, every week (day, year, month…), once a week, on Sundays, etc.

基本结构：①be动词；②行为动词

否定形式：①am/is/are+not;②此时态的谓语动词若为行为动词，则在其前加don't,如主语为第三人称单数，则用doesn't，同时还原行为动词。

一般疑问句：①把be动词放于句首；②用助动词do提问，如主语为第三人称单数，则用does，同时，还原行为动词。

　例：I'll go with you when I finish(finish) my homework.

　　 答案：have finished

　　 解析：在条件、时间状语从句中表示将来完成的动作，用现在完成时。但注意，此时表示这动作将在另一动作之前完成，若两动作同时发生，或几乎同时发生，则一般不用现在完成时。

　　 另外，现在完成时易与一般过去时弄混，前边已经讲过,这里不在重复．

　　 例：I have already finished my homework.(变一般疑问句)

　　　　 Have you already finished your homework?

　　 答案： Have you finished your homework yet?

　　 解析：现在完成时态中，肯定句中有already，变否定句或疑问句时通常要改为yet．

　　 例：我去过北京。

　　 I have gone to Beijing.

　　 答案：I have been to Beijing.

　　 解析："have been to+地点" 是表示曾去过某地，但此刻不在那儿(即在说话的地方)。而"have gone to+地点" 是表示去某地了，此刻在路上或已经到了那个地方(即不在说话的地方)。注意：这两个句式后接副词时，需省to。E.g. He has gone there.

1 Have you ever ______(take) a train?

2 It _________(be ) more than three years since Jim ______(leave) here.

3 Have you _____(make)friends with your new classmates yet?

4 I _______(have) my lunch and I'm not hungry now.

5 Jim has never seen a panda, _____he?

6 We ______(be) good friends since we met at school.

7 We can't find him anywhere. Perhaps he______(go) home.

8 He _____(read) the book before.

9 Mr. Green _____(teach) us a lot about social studies since September.

10 I _____never____ (meet) her sister before.

答案：1 taken　 2 has been, left　 3made　 4 have had　 5 has 6 have been　 7 has gone　 8 has read　 9 has taught　 10 have met

1 You have _____ a tall young man.

　A grown　 B grown　 into　 C grown us　 D grown up

2 He has ____ the watch for a year.

　A buy　 B bought　 C have　 D had

3 Has your brother _____ the dog?

　A kept in　 B fed 　C fed on　 D kept on

4I _____this book for two weeks, I have to return it now.

A borrowed　 B have　 borrowed　 C kept　 D have kept

5 Have you ever _____to the Great Wall? It's very beautiful.

　A gone　 B been　 C went　 D go

6 Her brother _____the Party since 1978.

　 A joined　 B has joined　 C has been in　 D was in　

7 The Greens _____many places of interest since they came to China.

　A will visit　 B visited　 C have visited　 D visit

8 I'm sorry, I ____ your name.

　A had forgotten　 B forgot　 C have forgotten　 D forgotten

9 The bookshop _____ for eight years.

　A has been open　 B has been opened　 Chas opened　 D has open

10 We have　　　 all the paper so we need to buy some.

　A used up　 B made of　 C filled with　 D hunted for

11 The flower I ____grown up.

　A planted has　 B planted have　 C has planted　 D have planted

　 答案：1B　 2 D　 3 B　 4D　 5 B　 6 C　 7 C　 8 C　 9 A　 10 A　 11 A

　　　 例：She has left (离开) for 2 hours.

　 答案：has been away

　　 解析：在肯定句中，与since或for引出的时间状语连用的是延续性动词，不能是短暂性动词，但在否定句中短暂性动词也是可以的。E.g. I haven't bought clothes for one year. 在此题中leave是短暂性动词，不能与for+时间段连用，须把它改成相应的延续性动词。如stop be over等。此题中leave要改成be away。这两种词的转换是学习现在完成时需要注意的。

专项练习：

　　 例：I has never heard (hear) of that before.

　　 答案：have heard

解析：现在完成时与一般现在时一样也有单三人称的变化，当单三人称作主语时用 has, 一般人称作主语时用have．

　例：He taken (take) the medicine before.

　　 答案：has taken

　　 解析：have/has 为助动词，起构成时态的作用，是不能省略的。我们可以这样记：“现在完成时态中，have/has 不可缺。”

1 She said the bus _______(leave) at five the next morning.

2 I wasn't sure whether he _______(lend) me his book the next morning.

3 He was fifty-six. In two years he _______(be) fifty-eight.

4 Whenever she has time, she ______(help) them in their work.

　答案：1 was leaving　　 2 would lend　　 3 would be　　 4 would help