We have three spare rooms, none of which can be used. ✬

Can you spare me a few minutes of your valuable time? ✬

I have a spare key to my house hidden outside. ✬

Can you spare me a few minutes? ✬

Excuse me, could you spare me a few minutes? I have a favor to ask you. ✬

Do you have a few minutes to spare? ✬

What do you do in your spare time? ✬

Could you spare me a few minutes? ✬

I have a few minutes to spare. ✬

Can you spare a buck? ✬