English verb conjugation
MUST SHIRR

Regular verb: shirr - shirred - shirred

Affirmation

Simple form	V-ing form
I must shirr you must shirr he must shirr we must shirr you must shirr they must shirr	I must be shirring you must be shirring he must be shirring we must be shirring you must be shirring they must be shirring
Perfect	V-ing perfect
I must have shirred you must have shirred he must have shirred we must have shirred you must have shirred they must have shirred	I must have been shirring you must have been shirring he must have been shirring we must have been shirring you must have been shirring they must have been shirring

Negation

Simple form	V-ing form
I mustn't shirr you mustn't shirr he mustn't shirr we mustn't shirr you mustn't shirr they mustn't shirr	I mustn't be shirring you mustn't be shirring he mustn't be shirring we mustn't be shirring you mustn't be shirring they mustn't be shirring
Perfect	V-ing perfect
I mustn't have shirred you mustn't have shirred he mustn't have shirred we mustn't have shirred you mustn't have shirred they mustn't have shirred	I mustn't have been shirring you mustn't have been shirring he mustn't have been shirring we mustn't have been shirring you mustn't have been shirring they mustn't have been shirring

Interrogative form

Simple form	V-ing form
must I shirr? must you shirr? must he shirr? must we shirr? must you shirr? must they shirr?	must I be shirring? must you be shirring? must he be shirring? must we be shirring? must you be shirring? must they be shirring?
Perfect	V-ing perfect
must I have shirred? must you have shirred? must he have shirred? must we have shirred? must you have shirred? must they have shirred?	must I have been shirring? must you have been shirring? must he have been shirring? must we have been shirring? must you have been shirring? must they have been shirring?

Interro-negative form

Simple form	V-ing form
mustn't I shirr? mustn't you shirr? mustn't he shirr? mustn't we shirr? mustn't you shirr? mustn't they shirr?	mustn't I be shirring? mustn't you be shirring? mustn't he be shirring? mustn't we be shirring? mustn't you be shirring? mustn't they be shirring?
Perfect	V-ing perfect
mustn't I have shirred? mustn't you have shirred? mustn't he have shirred? mustn't we have shirred? mustn't you have shirred? mustn't they have shirred?	mustn't I have been shirring? mustn't you have been shirring? mustn't he have been shirring? mustn't we have been shirring? mustn't you have been shirring? mustn't they have been shirring?