I must think you must think he must think we must think you must think they must think
V-ing form
I must be thinking you must be thinking he must be thinking we must be thinking you must be thinking they must be thinking
Perfect
I must have thought you must have thought he must have thought we must have thought you must have thought they must have thought
V-ing perfect
I must have been thinking you must have been thinking he must have been thinking we must have been thinking you must have been thinking they must have been thinking
Negation
Simple form
I must not think you must not think he must not think we must not think you must not think they must not think
V-ing form
I must not be thinking you must not be thinking he must not be thinking we must not be thinking you must not be thinking they must not be thinking
Perfect
I must not have thought you must not have thought he must not have thought we must not have thought you must not have thought they must not have thought
V-ing perfect
I must not have been thinking you must not have been thinking he must not have been thinking we must not have been thinking you must not have been thinking they must not have been thinking
Interrogative form
Simple form
must I think? must you think? must he think? must we think? must you think? must they think?
V-ing form
must I be thinking? must you be thinking? must he be thinking? must we be thinking? must you be thinking? must they be thinking?
Perfect
must I have thought? must you have thought? must he have thought? must we have thought? must you have thought? must they have thought?
V-ing perfect
must I have been thinking? must you have been thinking? must he have been thinking? must we have been thinking? must you have been thinking? must they have been thinking?
Interro-negative form
Simple form
must I not think? must you not think? must he not think? must we not think? must you not think? must they not think?
V-ing form
must I not be thinking? must you not be thinking? must he not be thinking? must we not be thinking? must you not be thinking? must they not be thinking?
Perfect
must I not have thought? must you not have thought? must he not have thought? must we not have thought? must you not have thought? must they not have thought?
V-ing perfect
must I not have been thinking? must you not have been thinking? must he not have been thinking? must we not have been thinking? must you not have been thinking? must they not have been thinking?