1.have trouble with:
与……有纠纷，有……的病痛

例句：I'm still having trouble with this math problem.
我依然为这道数学题目而苦恼。

2.stop off:
中途停留

例句：We stopped off at a hotel for the night.
我们中途停下来在一家旅馆住了一宿。

常用口语：How old are you?  Could I speak to someone?