who pays gift taxes?

sorry for this stupid question, but if you make a gift of “xxx” usd to somebody… do you pay gift tax? I thought the receiver of the gift is the one that should pay thx (assuming for exam purposes, so I guess in a USA context)

I would assume the receiver.

so when you transfer them to “trusts”, either the beneficiaries pay the gift tax (if any) or the trust pays the gift tax (if any) is this correct?

No, I am quite sure the grantor pays the tax. Certainly in the UK, you want to give you relative £10k, you gotta pay tax on £7k (there is a £3k gift tax allowance). In the context of a trust, this also makes sense (that the grantor should pay). Consider me setting up a trust for my nephew. I pay in £1m and the gift tax rate is, say, 20%. Where is my nephew going to find £200k for the tax bill. Finally I would say it makes sense because the grantor is the one making the gift.