I must sew you must sew she must sew we must sew you must sew they must sew
V-ing form
I must be sewing you must be sewing she must be sewing we must be sewing you must be sewing they must be sewing
Perfect
I must have sewn you must have sewn she must have sewn we must have sewn you must have sewn they must have sewn
V-ing perfect
I must have been sewing you must have been sewing she must have been sewing we must have been sewing you must have been sewing they must have been sewing
Negation
Simple form
I mustn't sew you mustn't sew she mustn't sew we mustn't sew you mustn't sew they mustn't sew
V-ing form
I mustn't be sewing you mustn't be sewing she mustn't be sewing we mustn't be sewing you mustn't be sewing they mustn't be sewing
Perfect
I mustn't have sewn you mustn't have sewn she mustn't have sewn we mustn't have sewn you mustn't have sewn they mustn't have sewn
V-ing perfect
I mustn't have been sewing you mustn't have been sewing she mustn't have been sewing we mustn't have been sewing you mustn't have been sewing they mustn't have been sewing
Interrogative form
Simple form
must I sew? must you sew? must she sew? must we sew? must you sew? must they sew?
V-ing form
must I be sewing? must you be sewing? must she be sewing? must we be sewing? must you be sewing? must they be sewing?
Perfect
must I have sewn? must you have sewn? must she have sewn? must we have sewn? must you have sewn? must they have sewn?
V-ing perfect
must I have been sewing? must you have been sewing? must she have been sewing? must we have been sewing? must you have been sewing? must they have been sewing?
Interro-negative form
Simple form
mustn't I sew? mustn't you sew? mustn't she sew? mustn't we sew? mustn't you sew? mustn't they sew?
V-ing form
mustn't I be sewing? mustn't you be sewing? mustn't she be sewing? mustn't we be sewing? mustn't you be sewing? mustn't they be sewing?
Perfect
mustn't I have sewn? mustn't you have sewn? mustn't she have sewn? mustn't we have sewn? mustn't you have sewn? mustn't they have sewn?
V-ing perfect
mustn't I have been sewing? mustn't you have been sewing? mustn't she have been sewing? mustn't we have been sewing? mustn't you have been sewing? mustn't they have been sewing?