o
obedecer
objetivo (m)
objeto (m) 
obligar
obligatorio(a)
obra (f)
obrarto
obrero 
obsequiar
observar 
obtener (e-ie)
obvio(a)
occidental 
océano (m) 
Océano Atlántico (m)
Océano Pacífico (m)
ochocientos(as)
octavo
octubre
ocultarse
ocupado(a) 
ocupar 
ocurrir  
oeste (m)
oferta (f)   
oficina (f)
oficina de correos (f)
ofrecer
oído (m)
oír 
ojo (m) 
ola (f) 
oler (o-ue)
oliva (f)
olvidar 
omnivoro(a)
onza (f)
opción (f)
opcional
operario
opereta (f)
opinar 
oponer
oración (f)
orangután (m)
ordenar 
oreja (f)
orgánico(a)
organismo (m)
organizar
oriental
origen (m) 
originario(a)
orilla (f)  
oro (m)
orquestra (f)
osar
oso (m) 
otoño (m)
otro, otra, otros, otras
out (m) 
ovación (f) 
ovalado(a) 
oveja (f)
oye

or
to obey
objective
object
to force
required
work
to work
worker
to entertain, regale, compliment, court, woo
to observe
to obtain, get
obvious
western
ocean
Atlantic Ocean
Pacific Ocean
800
eighth
October
to hide oneself
busy
to occupy
to occur, happen
west
offer
office
post office
to offer
inner ear
to hear
eye
wave
to smell
olive
to forget
omnivorous
ounce
option
optional
operator, worker
operetta
to think
to oppose
sentence
orangutan
to straighten-up, arrange, order
outer ear
organic
organism
to organize, arrange, set up
eastern
origen
originating, native
bank of a river
gold
orchestra
to dare, venture
bear
fall, autumn
other, others
out (baseball)
ovation
oval
sheep
listen