Verbal Ability - Sentence Improvement - Discussion

ing form is used with 'for' not with to. The sentence itself is correct.

But why can't listen be used in place of hear and hearing?

Here 'to' is a proposition and 'hearing' is a noun. This structure 'to+ing' is known as gerund. Hence given one is correct.

Hearing is not suitable for sentense.

Hearing means "The act of hearing attentively".

Ex: "they make good music--you should give them a hearing".

So we can use hearing here.

How can we use to with ING.

For ex-we cannot say-i want 2 writing a letter?

to hear can be replaced with hearing. replacing with only hear seems wrong
--------We look forward hearing from you

The word "to" in this phrase is slightly confusing because it is usually used to introduce a verb, as in "want to" or "have to". However, "look forward to" follows a different pattern:

I look forward to [a thing you would like to happen; a noun]

Obviously, "hear" is not a thing, so it wouldn’t make much sense to "look forward to hear from you". The thing you are looking forward to is "hearing from you":

[correct]: I look forward to hearing from you.
[wrong]: I look forward to hear from you.

[correct]: I am looking forward to hearing from you.
[wrong]: I am looking forward to hear from you.

The reason is that "to" is just a preposition here and has nothing to do with the infinitive, just like in "listen to" - you would say "I listen to singing" rather than "I listen to sing", wouldn’t you?

Ref: https://jakubmarian.com/i-am-looking-forward-to-hear-hearing-from-you/

I think that hearing is not the correct word, infact none of the words suit the sentence correctly. I suggest I request you to please explain how "hearing" was choose as the correct word.