I must knot you must knot he must knot we must knot you must knot they must knot
V-ing form
I must be knotting you must be knotting he must be knotting we must be knotting you must be knotting they must be knotting
Perfect
I must have knotted you must have knotted he must have knotted we must have knotted you must have knotted they must have knotted
V-ing perfect
I must have been knotting you must have been knotting he must have been knotting we must have been knotting you must have been knotting they must have been knotting
Negation
Simple form
I mustn't knot you mustn't knot he mustn't knot we mustn't knot you mustn't knot they mustn't knot
V-ing form
I mustn't be knotting you mustn't be knotting he mustn't be knotting we mustn't be knotting you mustn't be knotting they mustn't be knotting
Perfect
I mustn't have knotted you mustn't have knotted he mustn't have knotted we mustn't have knotted you mustn't have knotted they mustn't have knotted
V-ing perfect
I mustn't have been knotting you mustn't have been knotting he mustn't have been knotting we mustn't have been knotting you mustn't have been knotting they mustn't have been knotting
Interrogative form
Simple form
must I knot? must you knot? must he knot? must we knot? must you knot? must they knot?
V-ing form
must I be knotting? must you be knotting? must he be knotting? must we be knotting? must you be knotting? must they be knotting?
Perfect
must I have knotted? must you have knotted? must he have knotted? must we have knotted? must you have knotted? must they have knotted?
V-ing perfect
must I have been knotting? must you have been knotting? must he have been knotting? must we have been knotting? must you have been knotting? must they have been knotting?
Interro-negative form
Simple form
mustn't I knot? mustn't you knot? mustn't he knot? mustn't we knot? mustn't you knot? mustn't they knot?
V-ing form
mustn't I be knotting? mustn't you be knotting? mustn't he be knotting? mustn't we be knotting? mustn't you be knotting? mustn't they be knotting?
Perfect
mustn't I have knotted? mustn't you have knotted? mustn't he have knotted? mustn't we have knotted? mustn't you have knotted? mustn't they have knotted?
V-ing perfect
mustn't I have been knotting? mustn't you have been knotting? mustn't he have been knotting? mustn't we have been knotting? mustn't you have been knotting? mustn't they have been knotting?