情态动词如must ,could ,would等等后面什么时候加be动词?In law,you needn't to answer these problems.I needn't type this report today.情态动词后面不是加动词原形吗。为什么第一个句子要加to 第二个句子不加to

情态动词的用法,can,may,must,need,could,dared need情态动词的过去式是什么?need情态动词的过去式是什么如can是could 情态动词+have done 如 could have done,must have done,should have done 等等在如他么的否定词表示什么意思? must是情态动词吗? 情态动词造句can (could),may (might),must shall (should,will (would) need 情态动词can,could,may,must,need,have to的用法 should must can could will would may might情态动词造句拜托了··· 情态动词的回答形式有may need must could的提问分别怎么回答 must can 表推测时,是情态动词还是一般的动词?如题 求情态动词can、could、must、have to和should的练习题共20道题（全选择题也行,最好是每个情态动词有4道练习题, must 情态还是助动词难道是情态动词属于助动词?恭喜你,你说对了.在英语里,所有的情态动词（如must,can,may等）都是助动词.换句话说,情态动词是助动词的一部分.这理论对么? 情态动词如must ,could ,would等等后面什么时候加be动词?In law,you needn't to answer these problems.I needn't type this report today.情态动词后面不是加动词原形吗。为什么第一个句子要加to 第二个句子不加to must be是情态动词吗情态动词是什么 怎么才能认出情态动词? 情态动词(must,may,can,shall,might,could,will,should,need)引导的一般疑问句的肯定和否定回答 casn ,may,must,need情态动词用法 怎样使用情态动词shall/should/must 情态动词can,have to,must用法 怎样使用情态动词shall/should/must