couldn't是过去式吗

couldn't是过去式吗 couldn't是can't的过去式吗couldn't的原型是can't吗?0 - 离问题结束还有 14 天 23 小时 couldn't的原型是can't吗?couldn't是过去式吗 couldn't后面是不可以加动词过去式?这是什么语法? 请问英语过去式的语法Why couldn't he decide这句话是一般过去式,decide为什么不用过去式decided谢谢 It couldn’t be better 为什么用过去式 I couldn't hear you clearly.这里的could是can的过去式吗?还是作助动词,表示允许、许可]能,可以?I couldn't hear you clearly.这里的could只是can能的过去式吗?还是作助动词,表示允许、许可]能,可以?还是[用 He said he couldn't understand people who talked fast,为什么用过去式?这样的句式有什么规律吗? couldn't be 是表示肯定的意思吗? musten't是must过去式吗 not的过去式是don't吗 过去式发音是t 英文 前面过去式 后面未来式She was so frightened that she ________________________.A.couldn't speakB.won't be able to speak两个只能选一个,B是成立的吗?这样前面过去式,后面未来式可以吗还是wouldn't才是对的? can作为情态动词时没有过去式?情态动词不是没有过去式的吗那could和might又是什么啊China _____send people to space before ,but now.凭语感的话 肯定是couldn‘t,但想了一下,情态动词没有过去式,就填can’ the boy looked for his toy everywhere,but he couldn't find it.为什么是find不是found,因为前面是过去式啊looked for If you want better grades,you ______ watch so much TV.答案是shouldn't ,可以用couldn't吗shouldn't ,couldn't ,有什么区别呢 He said he couldn't follow me.句中couldn't能换成can't吗?He said he couldn't follow me.他说他跟不上我表示过去的能力时只能用can的过去式could吗?我查了资料又说了许多表示过去能力不用could的情况,感觉好 couldn't 是can't的过去词吗?是不是呢? couldn't 同义句为什么要变过去式用适当的动词和情态动词填空 They couldn't find any secrets.=They ( )not( )to find any secrets.was able问：1.为什么不是were,able2.能否是are ,able？抑或因为could 是can 的过去式