2.行为动词的变化。

　　否定句：主语+ don't( doesn't ) +动词原形(+其它)。如：

　　I don't like bread.

　　当主语为第三人称单数时，要用doesn't构成否定句。如：

　　He doesn't often play.

　　一般疑问句：Do( Does ) +主语+动词原形+其它。如：

　　- Do you often play football?

　　- Yes, I do. / No, I don't.

　　当主语为第三人称单数时，要用does构成一般疑问句。如：

　　- Does she go to work by bike?

　　- Yes, she does. / No, she doesn't.

　　特殊疑问句：疑问词+一般疑问句。如：How does your father go to work?