English verb conjugation
MUST OBTAIN

Regular verb: obtain - obtained - obtained

Affirmation

Simple form	V-ing form
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
Perfect	V-ing perfect
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

Negation

Simple form	V-ing form
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
Perfect	V-ing perfect
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

Interrogative form

Simple form	V-ing form
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?
Perfect	V-ing perfect
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?

Interro-negative form

Simple form	V-ing form
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?
Perfect	V-ing perfect
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?