Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I must gab gab you must gab gab she must gab gab we must gab gab you must gab gab they must gab gab
V-ing form
I must be gab gabing you must be gab gabing she must be gab gabing we must be gab gabing you must be gab gabing they must be gab gabing
Perfect
I must have gab gabed you must have gab gabed she must have gab gabed we must have gab gabed you must have gab gabed they must have gab gabed
V-ing perfect
I must have been gab gabing you must have been gab gabing she must have been gab gabing we must have been gab gabing you must have been gab gabing they must have been gab gabing
Negation
Simple form
I mustn't gab gab you mustn't gab gab she mustn't gab gab we mustn't gab gab you mustn't gab gab they mustn't gab gab
V-ing form
I mustn't be gab gabing you mustn't be gab gabing she mustn't be gab gabing we mustn't be gab gabing you mustn't be gab gabing they mustn't be gab gabing
Perfect
I mustn't have gab gabed you mustn't have gab gabed she mustn't have gab gabed we mustn't have gab gabed you mustn't have gab gabed they mustn't have gab gabed
V-ing perfect
I mustn't have been gab gabing you mustn't have been gab gabing she mustn't have been gab gabing we mustn't have been gab gabing you mustn't have been gab gabing they mustn't have been gab gabing
Interrogative form
Simple form
must I gab gab? must you gab gab? must she gab gab? must we gab gab? must you gab gab? must they gab gab?
V-ing form
must I be gab gabing? must you be gab gabing? must she be gab gabing? must we be gab gabing? must you be gab gabing? must they be gab gabing?
Perfect
must I have gab gabed? must you have gab gabed? must she have gab gabed? must we have gab gabed? must you have gab gabed? must they have gab gabed?
V-ing perfect
must I have been gab gabing? must you have been gab gabing? must she have been gab gabing? must we have been gab gabing? must you have been gab gabing? must they have been gab gabing?
Interro-negative form
Simple form
mustn't I gab gab? mustn't you gab gab? mustn't she gab gab? mustn't we gab gab? mustn't you gab gab? mustn't they gab gab?
V-ing form
mustn't I be gab gabing? mustn't you be gab gabing? mustn't she be gab gabing? mustn't we be gab gabing? mustn't you be gab gabing? mustn't they be gab gabing?
Perfect
mustn't I have gab gabed? mustn't you have gab gabed? mustn't she have gab gabed? mustn't we have gab gabed? mustn't you have gab gabed? mustn't they have gab gabed?
V-ing perfect
mustn't I have been gab gabing? mustn't you have been gab gabing? mustn't she have been gab gabing? mustn't we have been gab gabing? mustn't you have been gab gabing? mustn't they have been gab gabing?