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