A Premise

• must be a claim
• must be a single claim
• must be part of an argument (have a conclusion it is supporting)
• must be a claim that is supporting another claim

TEST
    Find the conclusion. Ask "Why? What makes you say so?" Say it out loud with "because" after it and then the potential premise.  Does it make sense?
   OR
    Say the potential premise out loud with a "therefore" after it, and then say the conclusion.  Does it sound right?

If the claim in question can be used to support any other claim (concealed or otherwise) in the argument it is a premise.
It is only a premise for the conclusion if it directly supports the conclusion.

A word (or several) of caution:

• Sometimes the premise is concealed. Is it underlying a question or is it implied but not stated outright?