How do I understand when to use “to” as preposition or should come before an infinite? Or, when do I have to use the infinite or the gerund after “to”? (as in I’m looking forward to meeting). I hope my question isn’t that confusing. Thanks for the answer, bye.
Hello Anon,

Can you write some examples of what you mean?

After I'm looking forward to ... use the gerund. The "to" goes with "looking forward to" -- it's not part of the verb that follows.
Try putting a noun or a pronoun, for example it, after to. If that is possible, to is a preposition, not a part of an infinitive, and the gerund should be used if you have a verb after to.

I am looking forward to it. OK, so:
I am looking forward to meeting him.

He used to it. WRONG! So:
He used to take a walk in the evenings. (Not: He used to taking...)

Teachers: We supply a list of EFL job vacancies
See 'To' + 'ing'.

Students: Are you brave enough to let our tutors analyse your pronunciation?
Cool Breeze you rock!