He can't be at home.为什么在at前面有be?什么情况下要加Be?

He can't be at home.为什么在at前面有be?什么情况下要加Be? he can't be at home与he may not be at home有什么不同?跪拜请求指点迷津. Tom _______(can’t/mustn't) be at home .he said he would go t He must be at home.为什么用be? 关于He can't be at home,isn't he?此句是否为反义疑问句? at home不是动词词组吗 为什么前面用be动词 例如He is not at home. He can't be at home.He went to the cinema.合并成一句话 为什么be in=be at home can't be at home可以转换成can't stay at home吗 There can't be anyone at home,___? Simon _____ be at home .He is on the playground.A.can't B.mu Tony wasn't at home yesterday .he might be