must obtain
Verbo regular: obtain - obtained- obtained

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must obtain
you must obtain
she must obtain
we must obtain
you must obtain
they must obtain 	I must be obtaining
you must be obtaining
she must be obtaining
we must be obtaining
you must be obtaining
they must be obtaining	I must have obtained
you must have obtained
she must have obtained
we must have obtained
you must have obtained
they must have obtained	I must have been obtaining
you must have been obtaining
she must have been obtaining
we must have been obtaining
you must have been obtaining
they must have been obtaining	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not obtain
you must not obtain
she must not obtain
we must not obtain
you must not obtain
they must not obtain 	I must not be obtaining
you must not be obtaining
she must not be obtaining
we must not be obtaining
you must not be obtaining
they must not be obtaining	I must not have obtained
you must not have obtained
she must not have obtained
we must not have obtained
you must not have obtained
they must not have obtained	I must not have been obtaining
you must not have been obtaining
she must not have been obtaining
we must not have been obtaining
you must not have been obtaining
they must not have been obtaining	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I obtain?
must you obtain?
must she obtain?
must we obtain?
must you obtain?
must they obtain? 	must I be obtaining?
must you be obtaining?
must she be obtaining?
must we be obtaining?
must you be obtaining?
must they be obtaining? 	must I have obtained?
must you have obtained?
must she have obtained?
must we have obtained?
must you have obtained?
must they have obtained? 	must I have been obtaining?
must you have been obtaining?
must she have been obtaining?
must we have been obtaining?
must you have been obtaining?
must they have been obtaining? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not obtain?
must you not obtain?
must she not obtain?
must we not obtain?
must you not obtain?
must they not obtain? 	must I not be obtaining?
must you not be obtaining?
must she not be obtaining?
must we not be obtaining?
must you not be obtaining?
must they not be obtaining? 	must I not have obtained?
must you not have obtained?
must she not have obtained?
must we not have obtained?
must you not have obtained?
must they not have obtained? 	must I not have been obtaining?
must you not have been obtaining?
must she not have been obtaining?
must we not have been obtaining?
must you not have been obtaining?
must they not have been obtaining?