English verb conjugation
MUST PURR

Regular verb: purr - purred - purred

Affirmation

Simple form	V-ing form
I must purr you must purr he must purr we must purr you must purr they must purr	I must be purring you must be purring he must be purring we must be purring you must be purring they must be purring
Perfect	V-ing perfect
I must have purred you must have purred he must have purred we must have purred you must have purred they must have purred	I must have been purring you must have been purring he must have been purring we must have been purring you must have been purring they must have been purring

Negation

Simple form	V-ing form
I mustn't purr you mustn't purr he mustn't purr we mustn't purr you mustn't purr they mustn't purr	I mustn't be purring you mustn't be purring he mustn't be purring we mustn't be purring you mustn't be purring they mustn't be purring
Perfect	V-ing perfect
I mustn't have purred you mustn't have purred he mustn't have purred we mustn't have purred you mustn't have purred they mustn't have purred	I mustn't have been purring you mustn't have been purring he mustn't have been purring we mustn't have been purring you mustn't have been purring they mustn't have been purring

Interrogative form

Simple form	V-ing form
must I purr? must you purr? must he purr? must we purr? must you purr? must they purr?	must I be purring? must you be purring? must he be purring? must we be purring? must you be purring? must they be purring?
Perfect	V-ing perfect
must I have purred? must you have purred? must he have purred? must we have purred? must you have purred? must they have purred?	must I have been purring? must you have been purring? must he have been purring? must we have been purring? must you have been purring? must they have been purring?

Interro-negative form

Simple form	V-ing form
mustn't I purr? mustn't you purr? mustn't he purr? mustn't we purr? mustn't you purr? mustn't they purr?	mustn't I be purring? mustn't you be purring? mustn't he be purring? mustn't we be purring? mustn't you be purring? mustn't they be purring?
Perfect	V-ing perfect
mustn't I have purred? mustn't you have purred? mustn't he have purred? mustn't we have purred? mustn't you have purred? mustn't they have purred?	mustn't I have been purring? mustn't you have been purring? mustn't he have been purring? mustn't we have been purring? mustn't you have been purring? mustn't they have been purring?