To say that you like something, you use the phrase me gusta. To say that your friend likes something, you say te gusta. To say that you/he/she like/likes, you say le gusta.
Examples:
Me gusta leer. - I like to read. No me gusta. - I don't like it. ¿Te gusta la camisa. - You like the shirt? A él le gusta el libro. - He likes the book.
To say that you hurt, you use the phrase me duele. To say that your friend hurts, you say te duele. To say that you/he/she hurt/hurts, you say le duele.
Me duele la cabeza. - My head hurts. Me duelen las rodillas. - My knees hurt.
¿Qué te duele? - What hurts? ¿Te duelen los brazos? - Do your arms hurt?
A él le duele la garganta. - His throat hurts. A él le duelen las rodillas. - His knees hurt.