"to + -ing"

[nurul `atiqah]

I am looking forward to receiving your reply.
She's committed to taking part.

I found both of the sentences correct. but,howcome it can be that way?

[rajan]

Please note that After preposition only Noun and Gerund Comes. Receving your reply and taking part is one of them.

Hope this will help you.

[Tdol]

It can be hard to see when 'to' is a preposition and when it is an infinitive marke, but any case like the first, where you have a phrasal verb with two prepositions after is, takes the gerund. There are also a number of verbs that do the same, like that one, object, etc.

[nurul `atiqah]

so the two "to" there is a preposition, is it?