反义疑问句:Sam had a meeting last night, didn't he?为什么是did而...答:Sam had a meeting last night,had是实义动词, 是动词have的过去式,变为反义疑问句时, 后半句要用助动词,这句是过去时, 所以用does的过去式did didn't he ?意思是 Sam昨天晚上开了个会, 不是吗?再比如说 We often play football in the afternoon.句子是一般现在时, 实义动词是play,反义...