Conjugación del verbo inglés
MUST FIRM

Verbo regular: firm - firmed - firmed

Afirmación

Forma simple	Forma con V-ing
I must firm you must firm he must firm we must firm you must firm they must firm	I must be firming you must be firming he must be firming we must be firming you must be firming they must be firming
Perfecto	Perfecto con V-ing
I must have firmed you must have firmed he must have firmed we must have firmed you must have firmed they must have firmed	I must have been firming you must have been firming he must have been firming we must have been firming you must have been firming they must have been firming

Negación

Forma simple	Forma con V-ing
I must not firm you must not firm he must not firm we must not firm you must not firm they must not firm	I must not be firming you must not be firming he must not be firming we must not be firming you must not be firming they must not be firming
Perfecto	Perfecto con V-ing
I must not have firmed you must not have firmed he must not have firmed we must not have firmed you must not have firmed they must not have firmed	I must not have been firming you must not have been firming he must not have been firming we must not have been firming you must not have been firming they must not have been firming

Forma interrogativa

Forma simple	Forma con V-ing
must I firm? must you firm? must he firm? must we firm? must you firm? must they firm?	must I be firming? must you be firming? must he be firming? must we be firming? must you be firming? must they be firming?
Perfecto	Perfecto con V-ing
must I have firmed? must you have firmed? must he have firmed? must we have firmed? must you have firmed? must they have firmed?	must I have been firming? must you have been firming? must he have been firming? must we have been firming? must you have been firming? must they have been firming?

Forma interro-negativa

Forma simple	Forma con V-ing
must I not firm? must you not firm? must he not firm? must we not firm? must you not firm? must they not firm?	must I not be firming? must you not be firming? must he not be firming? must we not be firming? must you not be firming? must they not be firming?
Perfecto	Perfecto con V-ing
must I not have firmed? must you not have firmed? must he not have firmed? must we not have firmed? must you not have firmed? must they not have firmed?	must I not have been firming? must you not have been firming? must he not have been firming? must we not have been firming? must you not have been firming? must they not have been firming?