- I stopped by at his office for a chat .
(Not: I stopped by at his office for having a chat.)
- I decided I would save up for a new computer.
(NOT: I decided I would save up for buying a new computer.)
- I popped into his office to have a chat.
- I decided to save up to buy a new computer.
For + verb-ing: the purpose of an object
However, if we are talking about the purpose of an object or an action, we normally use the for + verb-ing pattern. Note that this pattern commonly answers the question: What are they (used) for? Compare the following:
- Schools are for educating children not for entertaining
- Schools are for learning. Life is for living.
- This kitchen knife is especially useful for slicing vegetables.
- What's this for? ~ It's for opening oysters. It's
much better than a knife.
- What's this fifty pound note for? ~ It's for buying food for the weekend.
- I use this small knife to slice vegetables with.
- I use this gadget to open shellfish with.
(c) Adapted from http://www.bbc.co.uk/worldservice/learningenglish/grammar/learnit/learnitv284.shtml