[General] I look forward to hearing from you

[angelene001]

I look forward to hearing from you.

Can I use this expression in an informal letter?
Or is it better for a formal letter?
In which of these letters it is more natural?

I thought that we use "I look forward to hearing from you" in formal letters and "Looking forward to hearing from you" in informal ones.

 

[Jigster]

I am not a teacher.
The only real difference I see here is that the first example is a full sentence where the second is just a torso (it is missing the subject) and that is why it should be considered wrong in formal correspondence. I also see absolutely nothing wrong in using the first sentence in informal correspondence, as there is no rule against using nice and proper language in it.

 

[5jj]

The second is not a complete sentence grammatically, though it's hardly a fragment. It's a perfectly acceptable expression for less formal correspondence. The word 'torso' does not work here. The phrase 'nice and proper language' is not natural.

Expressions such as 'With best wishes' and 'With kind Regards' also lack a subject, but are also perfectly acceptable.