To, for, so that

To talk about purpose, or the reason why we do things, we can use for + verb-ing, we can use the infinitive with to, and we can use so that + subject + verb.

Noun or pronoun

'for' + verb-ing

I'm bringing some pots and pans...for cooking

Action or event

Infinitive with 'to'

We've got some water...to make tea

Action or event

'so that' + subject + verb

I'm taking some extra blankets...so that we don't get cold