Question

I know we must use to + infinitive when expressing purpose.

Like in """ I´ve come to help you"

However I´ve come across many sentences in which for + gerund is used. When can I use this type? Any rules?

Like in ""Another reason for doing it is...."

Thanks

Answer 1

Hello! for can be combined with a gerund clause. As a guide, the sentence you will create must answer this question "What is it for?"

For example:
The scissor is for cutting the ribbon during the show.
The white box contains a solution that is used for cleaning the table.

I hope this helps!

Answer 2

You can use the questions:

• what to do?
• for what?

Hope that helps.