The ask.

People who constantly ask is a huge giveaway. Can you do me a favor? Can you help me out with X? Can you talk to Y person for me? Can you lend me Z?

True friends are typically givers. Doesn’t have to be material things, could be time, advice, a helping hand, etc.

Another big one is negativity.

Negative people always attract issues and problems. For example: you go with them to watch a movie and they start a fight with someone in the parking lot, waiting in line, or shushing someone. If this happens frequently slow distance yourself. The toxicity is contagious.

Hang out with positive and ambitious people and that rubs off on you in a good way.