English verb conjugation MUST SUSTAIN

Regular verb: sustain - sustained - sustained

Affirmation

Simple form

I must sustain
you must sustain
he must sustain
we must sustain
you must sustain
they must sustain

V-ing form

I must be sustaining
you must be sustaining
he must be sustaining
we must be sustaining
you must be sustaining
they must be sustaining

Perfect

I must have sustained
you must have sustained
he must have sustained
we must have sustained
you must have sustained
they must have sustained

V-ing perfect

I must have been sustaining
you must have been sustaining
he must have been sustaining
we must have been sustaining
you must have been sustaining
they must have been sustaining

Negation

Simple form

I mustn't sustain
you mustn't sustain
he mustn't sustain
we mustn't sustain
you mustn't sustain
they mustn't sustain

V-ing form

I mustn't be sustaining
you mustn't be sustaining
he mustn't be sustaining
we mustn't be sustaining
you mustn't be sustaining
they mustn't be sustaining

Perfect

I mustn't have sustained
you mustn't have sustained
he mustn't have sustained
we mustn't have sustained
you mustn't have sustained
they mustn't have sustained

V-ing perfect

I mustn't have been sustaining
you mustn't have been sustaining
he mustn't have been sustaining
we mustn't have been sustaining
you mustn't have been sustaining
they mustn't have been sustaining

Interrogative form

Simple form

must I sustain?
must you sustain?
must he sustain?
must we sustain?
must you sustain?
must they sustain?

V-ing form

must I be sustaining?
must you be sustaining?
must he be sustaining?
must we be sustaining?
must you be sustaining?
must they be sustaining?

Perfect

must I have sustained?
must you have sustained?
must he have sustained?
must we have sustained?
must you have sustained?
must they have sustained?

V-ing perfect

must I have been sustaining?
must you have been sustaining?
must he have been sustaining?
must we have been sustaining?
must you have been sustaining?
must they have been sustaining?

Interro-negative form

Simple form

mustn't I sustain?
mustn't you sustain?
mustn't he sustain?
mustn't we sustain?
mustn't you sustain?
mustn't they sustain?

V-ing form

mustn't I be sustaining?
mustn't you be sustaining?
mustn't he be sustaining?
mustn't we be sustaining?
mustn't you be sustaining?
mustn't they be sustaining?

Perfect

mustn't I have sustained?
mustn't you have sustained?
mustn't he have sustained?
mustn't we have sustained?
mustn't you have sustained?
mustn't they have sustained?

V-ing perfect

mustn't I have been sustaining?
mustn't you have been sustaining?
mustn't he have been sustaining?
mustn't we have been sustaining?
mustn't you have been sustaining?
mustn't they have been sustaining?

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