1.肯定句：是指用肯定的語氣來陳述的句子，如：I'm a student. She is a doctor. He works in a hospital.

There are four fans in our classroom. He will eat lunch at 12:00. I watched TV yesterday evening.

2,否定句：含有否定詞或表示否定意義詞的句子，如：I'm not a student. She is not (isn't) a doctor.

He does not (doesn't) work in a hospital. There are not (aren't) four fans in our classroom.

He will not (won't) eat lunch at 12:00. I did not (didn't) watch TV yesterday evening.

☆注意☆ 小結(jié)：否定句主要是在肯定句的基礎(chǔ)上加上了否定詞 "not".有動詞be的句子則"not"加在be后面，可縮寫成"isn't,aren't",但am not 一般都分開寫。沒有動詞be的句子則要先在主要動詞的前面加上一個助動詞(do,does,did),然后在它后面加上"not",你也可以把它們縮寫在一起如"don't , doesn't , didn't ).這三個助動詞要根據(jù)人稱和時態(tài)來選擇，其中"does“只用于一般現(xiàn)在時主語是第三人稱單數(shù)的情況，而”did“只用于一般過去時，不論主語是什么人稱和數(shù)，都用”did" .

3,一般疑問句：是指詢問事實(shí)的句子，此類句子必須用"yes",或"no"來回答。

如：Are you a student Yes, I am / No, I'm not.

Is she a doctor Yes, she is. / No, she isn't.

Does he work in a hospital Yes, he does. / No, he doesn't.

Are there four fans in our classroom Yes, there are. / No, there aren't.

Are you going to buy a comic book tonight Yes, I am. / No, I am not. (Yes, we are. / No, we aren't.)

Will he eat lunch at 12:00 Yes, I will. / No, I will not(won't).

Are they swimming Yes, they are. / No, they aren't.

Did you watch TV yesterday evening Yes, I did. / No, I didn't.

☆注意☆ 小結(jié)：一般疑問句是在肯定句的基礎(chǔ)上，

①把動詞be調(diào)到首位，其他照寫，末尾標(biāo)點(diǎn)符號變成問號即可。

②沒有動詞be的句子則要在句首加上一個助動詞(do,does,did)再把緊跟在后面的動詞變回原形，末尾標(biāo)點(diǎn)符號變成問號即可。

這三個助動詞也要根據(jù)人稱和時態(tài)來選擇，其中"does“只用于一般現(xiàn)在時主語是第三人稱單數(shù)的情況，而”did“只用于一般過去時，不論主語是什么人稱和數(shù)，都用”did" .一般疑問句有個重要的原則就是問和答要一致，即問句里的第一個單詞(助動詞)和簡略答句里的這個詞是一致的。

今天就和大家就分享到這，祝愿同學(xué)們用辛勤的汗水去收獲美好的未來吧！