三年级小学生可以使用以下情态动词写句子：

Can（能/可以）：

I can swim.

Can you speak Chinese？

She can play the piano.

May（可以/也许）：

May I go home right now？

May I get other restroom？

Hemaybelateforschool.

Must（必须）：

Must I stand up？

You must finish your homework before playing with the dog.

Should（应该）：

You should respect your teacher.

We should start early.

Would（将会）：

I would go to Norway one day.

Would you like to come to my party？

这些句子展示了情态动词在日常生活中的基本用法，帮助三年级小学生理解和掌握这些重要的语言工具。