1: leap at his face and try to rip off his red nose. if it comes off and u hear the clown swear, u know hes a person. calmly walk away casually like nothing happened. If his nose is stuck to his face, u know he is a real clown. pull ur hand back as quickly as possible so it doesn't grab it and shove it in his mouth full of super sharp teeth.
2: run away as fast as u can. clowns cant run fast in clown shoes because they r like 10 sizes too big.
3: if u have nowhere to run, grab a sharp object and cut its suspenders. since they usually have really big pants, they should fall right down.