常与since+过去的时间点，for+一段时间，since+时间段+ego, so far等时间状语连用。
Eg. I have lived here for ten years.我已经住在这里了。(从前开始，持续到现在还住这儿)
Eg. I have lived here since . 自从我就住在这儿。(从开始，持续到现在还住这儿)
(3) 基本结构及句型转换：主语+have/has+过去分词(done) (当主语是第三人称单数has,其余人称用have。)
①肯定句：主语+have/has+过去分词+其他 I have finished my homework. (肯定句)
②否定句：主语+have/has+not+过去分词+其他 I have not finished my homework. (否定句)
③一般疑问句：Have/Has+主语+过去分词+其他
Have you finished your homework?
Yes, I have. / No, I haven t, (一般疑问句及肯定、否定回答)
(4)has gone (to), has been (to), has been (in) 的区别
? Have/Has gone(to) :去了(现在不在说话现场)
Eg. ---Where is your father?
---He has gone to Shanghai.
? Have/Has been (to) :去过(已不在去过的地方)
Eg. My father has been to Shanghai.
? Have/has been in：呆了多久(还在所呆的地方)
Eg. My father has been in Shanghai for two months. =My father has been in Shanghai since two months ago.
(5)现在完成时的标志：
①常与just, already, yet, ever, never, before, so far 等连用，强调动作的完成，不强调动作的持续。
Have you ever been to Japan? I have just finished my homework.
②for + 时间段;since + 过去的时间点;since + 段时间 ago;since + 一般过去时的句子。
They have known each other for five years. Since he was a child, he has lived in England.
(6)动词过去式和过去分词的变化
规则变化：1. 一般在动词词尾直接加ed。如：pick picked picked; wish wished wished; stay stayed stayed
2. 以不发音的e结尾的动词后面加d。如：like liked liked; hope hoped hoped; phone phoned phoned
3. 以―辅音字母 + y‖结尾的动词，变y为i，再加-ed。如：study studied studied; hurry hurried hurried; reply replied replied
4. 词尾只有一个辅音字母的重读闭音节动词，要双写辅音字母，再加-ed。如：stop stopped stopped; clap clapped clapped
不规则变化：
5. 以不变应万变。如：let let let; put put put; read read read
6. 若中间有双写e，则去掉一个e，单词末尾再加t。如：
feel felt felt; keep kept kept; sleep slept slept
7. 结尾的字母d变t。如：lend lent lent; build built built; send sent sent
8. 变为以-ought或-aught结尾。如：buy bought bought;
bring brought brought; catch caught caught; teach taught taught
【话题写作】
请你根据下表中所提供的信息以 Learn to express thanks 为题，用英语写一篇演讲稿。
背 景
1.认为上中学时吃好穿好是应该的;
