could

aux.v.

1. (表示允准)
   • Could I use your phone?
     让我用一下你的电话好吗?
2. (表示请求)
   • Could I come round next week?
     我下星期来拜访好吗?
3. (表示结果)
   • He studied very hard but couldn't pass his examination.
     他学习很努力, 但没能考及格。
4. (表示可能性)
   • It could be my mother.
     可能是我母亲。
5. (表示建议)
   • We could write a letter to the headmaster.
     我们不妨给校长写封信。