couldn't be 是表示肯定的意思吗?

It couldn't be worse 的汉语意思 couldn't放句首有难道的意思吗 I couldn't agree more.表示肯定还是否定? things couldn't be couldn't是过去式吗 请问：I couldn't care less.中的couldn't表示什么意思? couldn't 是can't的过去词吗? couldn't是can't的过去式吗 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 It couldn‘t be simpler怎么解释?是属于否定词加比较级 等于最高级的用法吗? couldn`t的意思和时态 couldn‘t什么意思?