Another pair of words that get transposed is “lend” and “loan.” Their usage is fairly simple:
Lend is a verb (past tense: lent). E.g.: That bank will lend money to anyone with a job. She lent me her dress for the party.
Loan is a noun. It refers to the thing that has been lent. E.g.: If you take out a student loan, you can’t get rid of it in bankruptcy.
“Loaned” is not a word. Banish it from your thoughts and your writing.