could和should的區別:
1. should可以用於第一人稱或第三人稱的疑問句中,表示徵求意見。
例如: My brother likes to listen to CDs. He often plays his CDs too loud. What should I do?
2. should 表示義務,可以用於提供建議,表示“應該”, 後面跟動詞原形。
例如: Maria argued with her mother last night. She is very upset now. What should she do? I think she should say sorry to her mother.
3. should也用於表示某事發生的可能性,用於表示推測的詞,意為“可能”。
例如: They should arrive soon.
4. could不僅僅是充當can的過去式,而且是一個單獨的情態動詞,表示“能;可以”,用來提供建議,後面跟動詞原形,它和should在意義上不同,前者是“可以”,後者是“應該”,表示不同的態度,但兩個都可以用來提供建議。
例如: You could borrow a bike to that park. I think you should have a talk with your friend.