jeden funt w drobnych in English:

Be a darling and lend us 20 quid, will you?

Can you lend me five quid?

Here's the six quid I owe you.

Could you lend me 20 quid (= £20), mate?

'How much is a whiskey on the rocks?' 'Five quid.'

Can you lend me a couple of quid?

I have only three quid left.

One pound (100 pence) in British Sterling (GBP). In very common use, all across the UK. That'll be a quid mate That's going to set you back about 3, 4 hundred quid bjutiful frejzal pipel 😊 I need twenty quid for petrol.

... situations where it's a quid pro quo or that...