I must prefix you must prefix he must prefix we must prefix you must prefix they must prefix
V-ing form
I must be prefixing you must be prefixing he must be prefixing we must be prefixing you must be prefixing they must be prefixing
Perfect
I must have prefixed you must have prefixed he must have prefixed we must have prefixed you must have prefixed they must have prefixed
V-ing perfect
I must have been prefixing you must have been prefixing he must have been prefixing we must have been prefixing you must have been prefixing they must have been prefixing
Negation
Simple form
I must not prefix you must not prefix he must not prefix we must not prefix you must not prefix they must not prefix
V-ing form
I must not be prefixing you must not be prefixing he must not be prefixing we must not be prefixing you must not be prefixing they must not be prefixing
Perfect
I must not have prefixed you must not have prefixed he must not have prefixed we must not have prefixed you must not have prefixed they must not have prefixed
V-ing perfect
I must not have been prefixing you must not have been prefixing he must not have been prefixing we must not have been prefixing you must not have been prefixing they must not have been prefixing
Interrogative form
Simple form
must I prefix? must you prefix? must he prefix? must we prefix? must you prefix? must they prefix?
V-ing form
must I be prefixing? must you be prefixing? must he be prefixing? must we be prefixing? must you be prefixing? must they be prefixing?
Perfect
must I have prefixed? must you have prefixed? must he have prefixed? must we have prefixed? must you have prefixed? must they have prefixed?
V-ing perfect
must I have been prefixing? must you have been prefixing? must he have been prefixing? must we have been prefixing? must you have been prefixing? must they have been prefixing?
Interro-negative form
Simple form
must I not prefix? must you not prefix? must he not prefix? must we not prefix? must you not prefix? must they not prefix?
V-ing form
must I not be prefixing? must you not be prefixing? must he not be prefixing? must we not be prefixing? must you not be prefixing? must they not be prefixing?
Perfect
must I not have prefixed? must you not have prefixed? must he not have prefixed? must we not have prefixed? must you not have prefixed? must they not have prefixed?
V-ing perfect
must I not have been prefixing? must you not have been prefixing? must he not have been prefixing? must we not have been prefixing? must you not have been prefixing? must they not have been prefixing?