sorry, I beg your pardon.
这是比较地道的说法。
你直接说Sorry,对方基本就知道了
I don't get it.
我没理解你的意思。
I can't understand you.
我无法理解你。(一般不要用,是指你知道他的字面意思,但是无法理解他说的话)
I can't follow you, could you speak slowly?
我跟不上你,可以说的慢一点吗
Pardon./I beg your pardon.
这个是地道的说法,意思是,我没有听明白你的意思,请再说一次,后者较前者语气要礼貌, 同样也可以用以下说法:
Sorry,I can not understand you.
I do not know your meaning.
I can not follow you.
I can not get you.
you can't make yourself understood.
i don't know what you meant.
i don't understand.
I can't catch what you mean.
i didnt get you.