English verb conjugation
MUST CURTAIN

Regular verb: curtain - curtained - curtained

Affirmation

Simple form	V-ing form
I must curtain you must curtain he must curtain we must curtain you must curtain they must curtain	I must be curtaining you must be curtaining he must be curtaining we must be curtaining you must be curtaining they must be curtaining
Perfect	V-ing perfect
I must have curtained you must have curtained he must have curtained we must have curtained you must have curtained they must have curtained	I must have been curtaining you must have been curtaining he must have been curtaining we must have been curtaining you must have been curtaining they must have been curtaining

Negation

Simple form	V-ing form
I mustn't curtain you mustn't curtain he mustn't curtain we mustn't curtain you mustn't curtain they mustn't curtain	I mustn't be curtaining you mustn't be curtaining he mustn't be curtaining we mustn't be curtaining you mustn't be curtaining they mustn't be curtaining
Perfect	V-ing perfect
I mustn't have curtained you mustn't have curtained he mustn't have curtained we mustn't have curtained you mustn't have curtained they mustn't have curtained	I mustn't have been curtaining you mustn't have been curtaining he mustn't have been curtaining we mustn't have been curtaining you mustn't have been curtaining they mustn't have been curtaining

Interrogative form

Simple form	V-ing form
must I curtain? must you curtain? must he curtain? must we curtain? must you curtain? must they curtain?	must I be curtaining? must you be curtaining? must he be curtaining? must we be curtaining? must you be curtaining? must they be curtaining?
Perfect	V-ing perfect
must I have curtained? must you have curtained? must he have curtained? must we have curtained? must you have curtained? must they have curtained?	must I have been curtaining? must you have been curtaining? must he have been curtaining? must we have been curtaining? must you have been curtaining? must they have been curtaining?

Interro-negative form

Simple form	V-ing form
mustn't I curtain? mustn't you curtain? mustn't he curtain? mustn't we curtain? mustn't you curtain? mustn't they curtain?	mustn't I be curtaining? mustn't you be curtaining? mustn't he be curtaining? mustn't we be curtaining? mustn't you be curtaining? mustn't they be curtaining?
Perfect	V-ing perfect
mustn't I have curtained? mustn't you have curtained? mustn't he have curtained? mustn't we have curtained? mustn't you have curtained? mustn't they have curtained?	mustn't I have been curtaining? mustn't you have been curtaining? mustn't he have been curtaining? mustn't we have been curtaining? mustn't you have been curtaining? mustn't they have been curtaining?