must doubt
Verbo regular: doubt - doubted- doubted

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must doubt
you must doubt
she must doubt
we must doubt
you must doubt
they must doubt 	I must be doubting
you must be doubting
she must be doubting
we must be doubting
you must be doubting
they must be doubting	I must have doubted
you must have doubted
she must have doubted
we must have doubted
you must have doubted
they must have doubted	I must have been doubting
you must have been doubting
she must have been doubting
we must have been doubting
you must have been doubting
they must have been doubting	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not doubt
you must not doubt
she must not doubt
we must not doubt
you must not doubt
they must not doubt 	I must not be doubting
you must not be doubting
she must not be doubting
we must not be doubting
you must not be doubting
they must not be doubting	I must not have doubted
you must not have doubted
she must not have doubted
we must not have doubted
you must not have doubted
they must not have doubted	I must not have been doubting
you must not have been doubting
she must not have been doubting
we must not have been doubting
you must not have been doubting
they must not have been doubting	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I doubt?
must you doubt?
must she doubt?
must we doubt?
must you doubt?
must they doubt? 	must I be doubting?
must you be doubting?
must she be doubting?
must we be doubting?
must you be doubting?
must they be doubting? 	must I have doubted?
must you have doubted?
must she have doubted?
must we have doubted?
must you have doubted?
must they have doubted? 	must I have been doubting?
must you have been doubting?
must she have been doubting?
must we have been doubting?
must you have been doubting?
must they have been doubting? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not doubt?
must you not doubt?
must she not doubt?
must we not doubt?
must you not doubt?
must they not doubt? 	must I not be doubting?
must you not be doubting?
must she not be doubting?
must we not be doubting?
must you not be doubting?
must they not be doubting? 	must I not have doubted?
must you not have doubted?
must she not have doubted?
must we not have doubted?
must you not have doubted?
must they not have doubted? 	must I not have been doubting?
must you not have been doubting?
must she not have been doubting?
must we not have been doubting?
must you not have been doubting?
must they not have been doubting?