I must double-tongue you must double-tongue he must double-tongue we must double-tongue you must double-tongue they must double-tongue
V-ing form
I must be double-tonguing you must be double-tonguing he must be double-tonguing we must be double-tonguing you must be double-tonguing they must be double-tonguing
Perfect
I must have double-tongued you must have double-tongued he must have double-tongued we must have double-tongued you must have double-tongued they must have double-tongued
V-ing perfect
I must have been double-tonguing you must have been double-tonguing he must have been double-tonguing we must have been double-tonguing you must have been double-tonguing they must have been double-tonguing
Negation
Simple form
I mustn't double-tongue you mustn't double-tongue he mustn't double-tongue we mustn't double-tongue you mustn't double-tongue they mustn't double-tongue
V-ing form
I mustn't be double-tonguing you mustn't be double-tonguing he mustn't be double-tonguing we mustn't be double-tonguing you mustn't be double-tonguing they mustn't be double-tonguing
Perfect
I mustn't have double-tongued you mustn't have double-tongued he mustn't have double-tongued we mustn't have double-tongued you mustn't have double-tongued they mustn't have double-tongued
V-ing perfect
I mustn't have been double-tonguing you mustn't have been double-tonguing he mustn't have been double-tonguing we mustn't have been double-tonguing you mustn't have been double-tonguing they mustn't have been double-tonguing
Interrogative form
Simple form
must I double-tongue? must you double-tongue? must he double-tongue? must we double-tongue? must you double-tongue? must they double-tongue?
V-ing form
must I be double-tonguing? must you be double-tonguing? must he be double-tonguing? must we be double-tonguing? must you be double-tonguing? must they be double-tonguing?
Perfect
must I have double-tongued? must you have double-tongued? must he have double-tongued? must we have double-tongued? must you have double-tongued? must they have double-tongued?
V-ing perfect
must I have been double-tonguing? must you have been double-tonguing? must he have been double-tonguing? must we have been double-tonguing? must you have been double-tonguing? must they have been double-tonguing?
Interro-negative form
Simple form
mustn't I double-tongue? mustn't you double-tongue? mustn't he double-tongue? mustn't we double-tongue? mustn't you double-tongue? mustn't they double-tongue?
V-ing form
mustn't I be double-tonguing? mustn't you be double-tonguing? mustn't he be double-tonguing? mustn't we be double-tonguing? mustn't you be double-tonguing? mustn't they be double-tonguing?
Perfect
mustn't I have double-tongued? mustn't you have double-tongued? mustn't he have double-tongued? mustn't we have double-tongued? mustn't you have double-tongued? mustn't they have double-tongued?
V-ing perfect
mustn't I have been double-tonguing? mustn't you have been double-tonguing? mustn't he have been double-tonguing? mustn't we have been double-tonguing? mustn't you have been double-tonguing? mustn't they have been double-tonguing?