M - er
mantener to maintain, to support, to sustain, to keep
merecer to deserve, 
meter to put, to place, insert, involve
moler to grind
morder to bite
mover to move
moverse to get the move on
N - er
nacer to be born, to hatch, to sprout
O - er
obedecer to obey  take orders; mind; answer 
obtener to obtain
ofender to offend
ofrecer to offer
oler to smel, to sniff
oponer to oppose
oponerse to be oppose
oscurecer to darken, to grow dark
obscurecer to darken, to grow dark
P - er
padecer to suffer, to endure, to be a victim
palidecer to turn pale
parecer to look like, to seem like
perder to lose, to waste, to miss
permanacer to stay, remain
pertenecer to belong
poder to be able to, can, may
poner to put, to place, to st
ponerse to put on (clothing), to put/place ( oneself), to   turn/get/become + adjetive of physical/mental state.
poseer to possess, to have, own
posponer to postpone, to put behind
predisponer to predispose
prender to pin, to attach, switch on, turn on
presuponer to presuppose
prevalecer to prevail
prever to take into account
proceder to procced, to act, 
prometer to promise, 
promover to promote, 
proponer to propose
proteger to protect
proveer to provide, to supply