Look forward to something means to be pleased or excited that it is going to happen. The ‘to’ in look forward to is a preposition, so we must follow it by a noun phrase or a verb in the -ing form:

I’m looking forward to the holidays.

Are you excited about your trip to South America?

Yes, I’m looking forward to it.

We’re looking forward to going to Switzerland next month.

Not: … looking forward to go to Switzerland …

If the second verb has a different subject, we use the object form of the pronoun, not the subject form:

We’re looking forward to him arriving next week.

Not: We’re looking forward to he arriving next week.

We also use look forward to at the end of formal letters and formal emails to say that we hope to hear from someone or expect that something will happen. We use the present simple form:

I look forward to your reply.

I look forward to hearing from you soon.

We look forward to receiving payment for the services detailed above.