must obtain
Verbo regular: obtain - obtained- obtained

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com 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	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I mustn't obtain
you mustn't obtain
she mustn't obtain
we mustn't obtain
you mustn't obtain
they mustn't obtain 	I mustn't be obtaining
you mustn't be obtaining
she mustn't be obtaining
we mustn't be obtaining
you mustn't be obtaining
they mustn't be obtaining	I mustn't have obtained
you mustn't have obtained
she mustn't have obtained
we mustn't have obtained
you mustn't have obtained
they mustn't have obtained	I mustn't have been obtaining
you mustn't have been obtaining
she mustn't have been obtaining
we mustn't have been obtaining
you mustn't have been obtaining
they mustn't have been obtaining	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com 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-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
mustn't I obtain?
mustn't you obtain?
mustn't she obtain?
mustn't we obtain?
mustn't you obtain?
mustn't they obtain? 	mustn't I be obtaining?
mustn't you be obtaining?
mustn't she be obtaining?
mustn't we be obtaining?
mustn't you be obtaining?
mustn't they be obtaining? 	mustn't I have obtained?
mustn't you have obtained?
mustn't she have obtained?
mustn't we have obtained?
mustn't you have obtained?
mustn't they have obtained? 	mustn't I have been obtaining?
mustn't you have been obtaining?
mustn't she have been obtaining?
mustn't we have been obtaining?
mustn't you have been obtaining?
mustn't they have been obtaining?