a brain/brains
Which is correct the singular or plural form?
pick someone's brain or pick someone's brains?
with someone's brains or with someone's brain?
rack someone's brain or rack someone's brains?

Thanks!

Question

a brain/brains
Which is correct the singular or plural form?
pick someone's brain or pick someone's brains?
with someone's brains or with someone's brain?
rack someone's brain or rack someone's brains?

Thanks!

Answer

both are used, but "pick your brain" gets more google hits
with someone's brain
both are used, but"racked my brains" gets more google hits