"Desear" (to wish; to desire)= feeling experienced by someone when think about possessing or doing something that is believed to be good or beneficial for someone. "Querer" (to want, to wish smth.; to love someone...)= in a sense related to "desear" could have a similar meaning. In the sense of to wish, to aspire, to expect... "Pensar" (to think, of, about...; to intend, to reflect on...)

desear : is when you imagine something what you want example: yo deseo un carro / i want a car Pensar : is only to think / example: she thinks that her dog is sick / ella PIENSA que su perro esta enfermo Querer: is want something but with a special or different feeling example: i want to be with you / yo QUIERO estar contigo