一般现在时
一. 意义：表示经常发生的事情,动作或存在的状态
二. 构成及变化
1.be动词的变化.
肯定句：主语+be(am,is,are)+其它.如： I am a boy.我是一个男孩.
否定句：主语+ be + not +其它.如：He is not a worker.他不是工人.
一般疑问句：Be +主语+其它. 如：-Are you a student? -Yes. I am. / No, I'm not.
特殊疑问句：疑问词+一般疑问句.如：Where is my bike?
2. 行为动词的变化.
当主语为第一,二人称及复数时,助动词为do
肯定句：主语+动词原形(+其它).如： We often play basketball after school.
否定句：主语+ don't+动词原形(+其它).如：we don’t play basketball after school.
一般疑问句：Do +主语+动词原形+其它?
如： Do you often play basketball after school l? Yes, we do. / No, we don't.
特殊疑问句：疑问词+以do开头的一般疑问句?
如： What do you often do after school ?
当主语为第三人称单数时 ,助动词为does
肯定句：主语+动词三单式(+其它).如： He swims well.
否定句：主语+ doesn’t+动词原形(+其它).如：He doesn’t swim well..
一般疑问句：Does +主语+动词原形+其它.
如：Does he swim well ? Yes, he does. / No, he doesn't.
特殊疑问句：疑问词+以does开头的一般疑问句?
如： How does your father go to work?
三.第三人称单数的动词变化规则(只有在第三人称为主语的肯定句中,动词才用三单式)
(1)多数动词直接加s:runs gets likes collets takes plays climbs…….
(2)结尾是s, x, sh, ch, o,前为辅音字母,
结尾加es :watches teaches goes does washes crosses mixes brushes
(3)动词末尾y前为辅音:将y改为i加es: study→studies fly→flies carry→carries cry→cries
但在y前如果为元音则直接加s:buys says
四.时间标志：always , usually , often , sometimes ,every…
现在进行时
一.意义——当表示现在正在进行的动作或正在发生的事.
二.构成:be (am, is ,are )+动词现在分词-ing形式
肯定句： 主语 + be + 现在分词V-ing (+ 其他) I’m doing my homework now .
否定句：主语+be+not+动词-ing +其他. I’m not doing my homework now.
一般疑问句：Be+主语+动词-ing +其他?
Are you doing your home work now? Yes, I am . No , I’m not .
特殊疑问句：特殊疑问词+be+主语+动词-ing+其他?What are you doing now ?
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