留学生在表达没听懂对方话语时，可以使用以下几种表达方式：
1. `Sorry, I didn't catch that.`
2. `Could you speak a bit slower, please？`
3. `Pardon？`
4. `I'm sorry, I didn't understand.`
5. `Could you please repeat that？`
6. `Would you mind going over that again？`
7. `Could you speak up a little？`
8. `I beg your pardon？`
使用这些表达方式时，通常是为了请求对方重复或放慢语速以便更好地理解。请根据具体情境选择合适的表达