...has he? ( If Sam is male) .. has she? (If Sam is female)

The trick is to figure out the verb or auxiliary verb. That verb MUST be used in the tag question. Sam's never been to Mexico. => Sam HAS never been..., HAS he? The tag question is the opposite of the verb in terms of positive and negative. He has been, hasn't he? (positive verb => negative tag) He has NEVER been, has he? (The "never" makes it negative. => positive tag) He hasn't been, has he? (negative verb => positive tag)

Welcome to italki, Margaret. Just in case you hadn't realised, if you want to reply to a query, you need to click on 'Answer this Question' rather than 'Add a comment'. That way you'll end up among the actual Answers, along with the rest of us, rather than hovering overhead in the Comments section! It also means that the fact that you've answered will appear on your personal profile.

Oops. Su.Ki is correct. My apologies.

Thank you!