Do you have to pay royalties when using quotes from people like Albert Einstein and how do you pay if you do?

Question

Do you have to pay royalties when using quotes from people like Albert Einstein and how do you pay if you do?

Answer 1

Possibly in a formal publication, but otherwise, no.

Anything that isn't public domain which you use in a book or whatever, you have to pay royalties, even if it is to their estate. Otherwise you could get sued.