Let's directly jump to the answer
1. When you look towards her/him, she/he instantly turns her eyes or face anywhere else.
2. When all people starts laughing (on a joke or someone), she/he stares at you to see your reaction.
3. She/he remembers your Birthday and do something special for you.
4. If she/he tries to sit or stand always around you or near you.
5. If she/he appears to be nervous while talking to you.
6. If she/he do not maintains eye contact while talking to you.
7. If her/his friends start looking at you, while discussing something away from you and she/he doesn't looks at you.
8. If she waits only for you every time for an event.
Note - At least 5 situations (given above) should match yours to make sure that he/she surely loves you.
If all situations match yours then it’s time to propose her/him.
Also tell your crush's name and whether she/he loves you or not in the comments below.