A practical english grammar - Vyssaja skola 1978

Gerunds after prepositions
Sound symbols

The gerund functions grammatically as a noun, and may be used as the object of a preposition. Although the infinitive can also be analyzed as a verbal noun in many sentences, it is never used as the object of a preposition in English. A large number of expressions whose last element is a preposition are followed by gerunds.

He’s fond of skating.

I’m tired of hearing about that.

We look forward to visiting you.

I don’t approve of gambling.

I don’t feel like going to bed yet.

I object to his doing that.