We can sometimes use for + ing to talk about the purpose of a thing. When we do, it means the same as to + infinitive.
- What is that for? It is for opening envelopes
- This bell is for calling the waiter.
- This bell is to call the waiter.
When we talk about the purpose of somebody’s actions, we cannot use for + ing.
- I went there to ask for help.
- To get tickets, you will have to queue for hours.
However, it is sometimes possible to use for + noun for this.
- I went there for help.
- You will have to queue for hours for tickets.
We can also use for + object + infinitive to talk about a purpose.
- I gave her a notebook for her to write down new English words she found.
- They sent a form for me to sign.
We also use the pattern for + object + infinitive in sentences after is or was.
- The plan is for us to get to Barcelona by lunchtime.
- The objective was for them to get the work finished by the end of last month..
We can add details to a noun by using the pattern for + object + infinitive
- That is an expensive place for them to stay.
- There is a lot of work for us to do.
- There is no need for you to be so aggressive.
We also use the pattern for + object + infinitive after certain verbs and adjectives.
- I am waiting for him to make the first move.
- I have arranged for you to see the bank manager tomorrow morning.
- We are keen for you to take the job.
- I think it would be good for you to take a break now.