How to tell if a girl likes you?

I hang around 3 girls. One is short (im 6'3") with blonde hair and blue eyes, shes kinda chunky but she is great to be around, i've known her for 3 years and she was my moms old student at her school. The second girl is about my height, with red hair (dyed) brown eyes, and she is completely obsessed with me (love or infatuation?), ive known her since 2nd grade. The third girl i've known since kindergarden and is about my height, she is kinda emo/goth but she is really perky and spontaneous, she has black hair with purple streaks in it, brown eyes but she went to a different school till now (10th grade) and she is really good friends with me. All three hang around me ALOT and i know that one of them (redhead) likes me but im not sure if it love or infatuation. The other 2 i have no clue.