Conjugación del verbo inglés
MUST BACK

Verbo regular: back - backed - backed

Afirmación

Forma simple	Forma con V-ing
I must back you must back he must back we must back you must back they must back	I must be backing you must be backing he must be backing we must be backing you must be backing they must be backing
Perfecto	Perfecto con V-ing
I must have backed you must have backed he must have backed we must have backed you must have backed they must have backed	I must have been backing you must have been backing he must have been backing we must have been backing you must have been backing they must have been backing

Negación

Forma simple	Forma con V-ing
I must not back you must not back he must not back we must not back you must not back they must not back	I must not be backing you must not be backing he must not be backing we must not be backing you must not be backing they must not be backing
Perfecto	Perfecto con V-ing
I must not have backed you must not have backed he must not have backed we must not have backed you must not have backed they must not have backed	I must not have been backing you must not have been backing he must not have been backing we must not have been backing you must not have been backing they must not have been backing

Forma interrogativa

Forma simple	Forma con V-ing
must I back? must you back? must he back? must we back? must you back? must they back?	must I be backing? must you be backing? must he be backing? must we be backing? must you be backing? must they be backing?
Perfecto	Perfecto con V-ing
must I have backed? must you have backed? must he have backed? must we have backed? must you have backed? must they have backed?	must I have been backing? must you have been backing? must he have been backing? must we have been backing? must you have been backing? must they have been backing?

Forma interro-negativa

Forma simple	Forma con V-ing
must I not back? must you not back? must he not back? must we not back? must you not back? must they not back?	must I not be backing? must you not be backing? must he not be backing? must we not be backing? must you not be backing? must they not be backing?
Perfecto	Perfecto con V-ing
must I not have backed? must you not have backed? must he not have backed? must we not have backed? must you not have backed? must they not have backed?	must I not have been backing? must you not have been backing? must he not have been backing? must we not have been backing? must you not have been backing? must they not have been backing?