obedecer
to obey
observar
to observe
obtener
to obtain, to get
ocultarse
to hide oneself
ocupar
to occupy
ocurrir
to occur, to happen
ofrecer
to offer
oír
to hear
oler
to smell, to scent
olvidar
to forget
oponer
to oppose
ordenar
to order, to command, to put in order, to arrange
organizar
to organize, to arrange, to set up
osar
to dare, to venture