Do you need a favour? Tim Bowen does us a special favour in explaining some collocations.
If you do someone a favour, you help them with something. A favour can be big, great, huge or even massive, as in ‘You’d be doing me a massive favour if you could help me find a hotel room for the night’. It can also be little, slight or small, as in ‘I have a small favour to ask you: I wonder if you could keep an eye on my flat for a couple of days while I’m away?’ In certain circumstances a favour can be special, as in ‘As a special favour, we were allowed to use the members-only bar’.
If someone does you a favour, you may wish to respond in some way. You can return, repay or reciprocate a favour, as in ‘I don’t want any payment. I’m sure you’ll return the favour one day’. If you want someone to do you a favour, you can ask a favour, as in ‘I wonder if I could ask a favour. Could you possibly give me a lift to the station?’
If you think someone should do you a favour, you expect or look for that favour, as in ‘We’re not expecting any favours from that referee. He never gives us anything’. If you have an obligation to do someone a favour, you owe them a favour, as in ‘After all he’s done for us, I think we owe him a favour or two’.
You can also do things as a favour, as in ‘I really don’t want to go to the dinner tonight. I’m only going as a favour to my parents’.