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