Four years old little girls has an IQ of Albert Einstein.
These are the signals that indicate that guy likes a girl. This may be a start from where a relationship develops. He tells someone that he finds a girl attractive. He gives a look that give up his cool external. He asks a question "are you looking anyone?" and expects an answer “No”. He changes his way of saying "Oh, hi," at a sudden, and continue to say "I don’t want to seem obvious, but I am interested in you." Sometimes a guy may straight forward to express his wishes regarding liking a girl.