If you like them
Ask questions in a casual (but direct) way.
“Hey, so, I’ve been feeling some connection between us and was just wondering if you’re feeling the same?”
“So I’ve been thinking…. Do you like me more than as a friend?”
“I’ve been wanting to talk to you about something. I have a crush on you and am curious if you feel the same way?”
If you don’t like them
Be casual and gentle when asking questions and/or turning someone down.
“I’ve noticed you doing some things that are kind of flirty toward me. Do you have a crush on me?”
“I have a feeling that you might like me, and I want you to know that I’m only interesting in being your friend.”
“When we hugged the other night I noticed you came really close to my face, like you were going to kiss me…. Was this intentional?”