the English they speak

[navi tasan]

My father is from Boston, my mother from New York and my stepdad from Kansas.

1) Is there any difference between their English?
2) is there any difference between the English they speak?
3) is there any difference between the English each of them speak?

Which of the sentence 1-3 works in this context?

 

[Tarheel]

I might say:

Are there any differences in the way they speak?

 

[probus]

I concur with @Tarheel, but if forced to choose from the options proposed by the OP I'd go with 3. 1 and 2 seem slightly unnatural to me.