Is there any difference?

1) when will he come back?

2) when will he be back?

3) when is he coming back?

4) when will he get back?

5) when is he getting back?

Question

Is there any difference?

1) when will he come back?

2) when will he be back?

3) when is he coming back?

4) when will he get back?

5) when is he getting back?

Answer

Hello! All these sentences are correct and you can use them interchangeably, but according to English grammar the "will" form expresses a more uncertain future, so the person speaking does not know whether he will be back or not, nor when he will be back. The "-ing" form, on the other hand, expresses a certainty that he will be back sometime, even if the speaker does not know when exactly. The "-ing" form is more informal, and more used in everyday communication.

Answer

I disagree that using "will" expresses more uncertainty that "-ing" forms. In North America at least there is no such difference, and I've never heard of such a distinction.

In general, I would say that the sentences with "will" sound slightly more formal, but not enough to worry about. You could use either in almost all cases. So I think the only difference between your five forms of this question is a subtle difference in formality.