Unit7 Teenagers should be allowed to choose their own clothes

1.语态：

　①英语有两种语态：主动语态和补动语态　

　　主动语态表示是动作的执行者

　　被动语态表示主语是动作的承受者　

　 Cats 　eat 　fish. 　　　（主动语态）猫吃鱼。

　 Fish is eaten by cats.　(被动语态)鱼被猫吃。

②被动语态的构成

　　由"助动词be ＋及物动词的过去分词"构成

　　助动词be 有人称、数和时态的变化，其变化规则与be 作为连系动词时完全一样。

时态 被动语态结构 例句 一般现在 时 am

are +过去分词

is English is spoken in many countries. 一般过去 时 was +过去分词

were + 过去分词 This bridge was built in 1989. 情 态

动 词 can/should

may +be+过去分词

must/...... The work must be done right now. ③被动语态的用法

当我们不知道谁是动作的执行者，或者没有必要指出谁是动作的执行者，或者只需强调动作的承受者时，要用被动语态。

2. allow sb. to do sth. 允许某人做某事（主动语态）如：

　 Mother allows me to watch TV every night. 妈妈允许我每晚看电视。

　be allowed to do sth. 被允许做某事（被动语态）如：

　　LiLy is allowed to go to Qinzhou. 莉莉被允许去钦州。

3. get their ears pierced 穿耳洞

　让/使（别人）做某事　 get sth. done(过去分词)

　　　　　　　　　　　 have sth. done 如：

　I get my car made. == I have my car made. 我让别人修好我的车

4. enough 足够　

　形容词＋enough 如：beautiful enough　足够漂亮

enough＋名词　如：enough food 足够食物

enough to 　足够...去做...　如：

　　　I have enough money to go to Beijing. 我有足够的钱去北京。

She is old enough to go to school.她够大去读书了。

5. stop doing sth. 停止做某事　Please stop speaking.请停止说话。

　　stop to do sth. 停止下来去做某事　Please stop to speak.

　　请停下来说话。

6. 看起来好像...sb. seem to do sth.

it seems that +从句

He seems to feel very sad.

It seems that he feels very sad. 他看起来好像很伤心。