我不懂英语.你说的我看不明白.请原谅.

我不懂英语.
I don't know English./I don't speak English.(很多美国人不说自己不懂某种语言,只说他们不说这语言.)
你说的我看不明白.请原谅.
Sorry.I don't know what you are talking about.

I don't understand English.
I couldn't make out what you said.
Please forgive me.

Please forgive me
I don't understand English?
I don't understand What you say ?

晕。。。楼上那么正经的英语写上去，人家相信吗？所以要翻得“中国”一点。。。哈哈

I don't know English well , Your words I can't understand , Please execuse me .

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当然，如果要标准些，可以说：

Please pardon ? I'm not good at English , and can't catch your words at all . I'm very very sorry.