English verb conjugation
MUST OBTAIN

Regular verb: obtain - obtained - obtained

Affirmation

Simple form	V-ing form
I must obtain you must obtain he must obtain we must obtain you must obtain they must obtain	I must be obtaining you must be obtaining he must be obtaining we must be obtaining you must be obtaining they must be obtaining
Perfect	V-ing perfect
I must have obtained you must have obtained he 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 he must have been obtaining we must have been obtaining you must have been obtaining they must have been obtaining

Negation

Simple form	V-ing form
I mustn't obtain you mustn't obtain he 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 he mustn't be obtaining we mustn't be obtaining you mustn't be obtaining they mustn't be obtaining
Perfect	V-ing perfect
I mustn't have obtained you mustn't have obtained he 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 he mustn't have been obtaining we mustn't have been obtaining you mustn't have been obtaining they mustn't have been obtaining

Interrogative form

Simple form	V-ing form
must I obtain? must you obtain? must he obtain? must we obtain? must you obtain? must they obtain?	must I be obtaining? must you be obtaining? must he be obtaining? must we be obtaining? must you be obtaining? must they be obtaining?
Perfect	V-ing perfect
must I have obtained? must you have obtained? must he 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 he have been obtaining? must we have been obtaining? must you have been obtaining? must they have been obtaining?

Interro-negative form

Simple form	V-ing form
mustn't I obtain? mustn't you obtain? mustn't he 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 he be obtaining? mustn't we be obtaining? mustn't you be obtaining? mustn't they be obtaining?
Perfect	V-ing perfect
mustn't I have obtained? mustn't you have obtained? mustn't he 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 he have been obtaining? mustn't we have been obtaining? mustn't you have been obtaining? mustn't they have been obtaining?