请问这里为什么要用过去式 Let’s go shopping on Saturday morning.
问题描述：
请问这里为什么要用过去式 Let’s go shopping on Saturday morning.
A： Let’s go shopping on Saturday morning. Are you free?
B： Yes, I could meet you just after 10. I’m free all afternoon. We could go for dinner early in the evening.
为什么B要用can的过去式来回答
答
could是情态动词,有时可不看作是can的过去时,当它单纯是情态动词而不是过去式时,语气比can委婉些