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 must not swallow you must not swallow he must not swallow we must not swallow you must not swallow they must not swallow
V-ing form
I must not be swallowing you must not be swallowing he must not be swallowing we must not be swallowing you must not be swallowing they must not be swallowing
Perfect
I must not have swallowed you must not have swallowed he must not have swallowed we must not have swallowed you must not have swallowed they must not have swallowed
V-ing perfect
I must not have been swallowing you must not have been swallowing he must not have been swallowing we must not have been swallowing you must not have been swallowing they must not 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
must I not swallow? must you not swallow? must he not swallow? must we not swallow? must you not swallow? must they not swallow?
V-ing form
must I not be swallowing? must you not be swallowing? must he not be swallowing? must we not be swallowing? must you not be swallowing? must they not be swallowing?
Perfect
must I not have swallowed? must you not have swallowed? must he not have swallowed? must we not have swallowed? must you not have swallowed? must they not have swallowed?
V-ing perfect
must I not have been swallowing? must you not have been swallowing? must he not have been swallowing? must we not have been swallowing? must you not have been swallowing? must they not have been swallowing?