请外国留学生做事时，可以使用以下几种表达方式：

正式场合

Excuse me, could you please help me？

Could you do me a favor？

Would you be so kind as to assist me？

非正式场合

Hey, can you help me out？

Sorry to bother you, but could you help me with this？

Do you have a moment to help me？

具体请求

Could you help me with my English？

Can you speak a little slower？

How do you pronounce this word？

How do you say this in English？

礼貌用语

I apologize for the inconvenience, but could you assist me？

Excuse me for asking, but would you mind helping me？

根据具体的情境和对方的习惯，可以选择合适的表达方式来请外国留学生帮忙。