be动词属于系动词, 在句子中主要表现为三种形式:am is、are。后面往往接形容词或名词做表语。如: (1)I’m young. (young形容词做表语) (2)He is a boy.( a boy名词做表语) 含有be动词的句子在进行否定、疑问句变化时,都要在be动词上变化。 (1)变为否定句:主语+be+ not+其他。即,直接在be后not. ①I’m a Chinese boy.(变为否定句) ②You are good. (变为否定句) ③He is strict with us. (变为否定句) ④She is from America. (变为否定句) 以上四个句子中都含有am、 is或are,变否定句时,直接在am 、is、are后面加上not.即: ①I’m not a Chinese boy. ②You are not good. ③He is not strict with us. ④She is not from America. (2)变为一般疑问句:Be+主语+其他?即把be动词提到主语的前面。注意:当肯定句主语为第一人称I和We时,变一般疑问句要变为第二人称,be动词也要相应的变为are.同样肯定句中的my和our 也要变为your. ① I am a boy. (变为一般疑问句) →Are you a student? ② We are good friends. (变为一般疑问句) →Are you good friends? ③ She is from America. (变为一般疑问句) →Is she from America? ④ He is strict with us. (变为一般疑问句) →Is he strict with us? (3)变特殊疑问句:一般的要求为“对划线部分提问”,即用特殊疑问词代替划线的部分,后接省略划线部分的一般疑问句(一般不再出现划线部分)。如: ① I’m well.(对划线部分提问) →How are you? ②She is from America. (对划线部分提问) →Where is she from?