A gerund (动名词) by itself rarely serves as a modifier (修饰语). But it is often part of a prepositional phrase (介词短语) that serves as a modifier (by pleasing the child, in trying to please the child, etc.)

Example:

A: Fortunately, by cutting the number of employees, the annual debt of the firm has decreased.

B: Fortunately, by cutting the number of employees, the firm has decreased its annual debt.

[Analysis: The implied subject of “cutting” is “the firm,” but “the firm” is present only as object of the preposition “of”. The subject of the sentence is “the annual debt”. It is not the debt that has laid off workers.（并非是债务解雇了员工，而是公司）]

A: After gaining some experience, there measures will gradually be introduced in other regions across the country.

B: After we have gained some experience, there measures will gradually be introduced in other regions across the country.