How do you know when ur in love?

Like what are the sighns i think im inlove with someone but how do i know like for example im looking for answer like you get nervous around them or u feel completly comfortable u stare at them alot ha orr something like that..does this question even make sense? Haha well thanks for anyone who answers..*sorry i think i said like alot and haha*..ha just thought id add that lil thing..eh..well thanks again! ;)