I pay the morgage intrest for my friends house, that is under his name. How do I claim that deduction? What forms do I need to fill out?

Unless your name is on the loan or the deed, you cannot claim anything at all.  You have given your friend a gift which is not deductible.  Sorry.

this is a rental property that we have unrecorded claimed deed. Does that change things?

Can you explain the situation?  Are you listed as owner on the unrecorded deed?  Why is it unrecorded?  Are you receiving the rent from the rental property?