I must gnaw you must gnaw he must gnaw we must gnaw you must gnaw they must gnaw
V-ing form
I must be gnawing you must be gnawing he must be gnawing we must be gnawing you must be gnawing they must be gnawing
Perfect
I must have gnawed you must have gnawed he must have gnawed we must have gnawed you must have gnawed they must have gnawed
V-ing perfect
I must have been gnawing you must have been gnawing he must have been gnawing we must have been gnawing you must have been gnawing they must have been gnawing
Negation
Simple form
I must not gnaw you must not gnaw he must not gnaw we must not gnaw you must not gnaw they must not gnaw
V-ing form
I must not be gnawing you must not be gnawing he must not be gnawing we must not be gnawing you must not be gnawing they must not be gnawing
Perfect
I must not have gnawed you must not have gnawed he must not have gnawed we must not have gnawed you must not have gnawed they must not have gnawed
V-ing perfect
I must not have been gnawing you must not have been gnawing he must not have been gnawing we must not have been gnawing you must not have been gnawing they must not have been gnawing
Interrogative form
Simple form
must I gnaw? must you gnaw? must he gnaw? must we gnaw? must you gnaw? must they gnaw?
V-ing form
must I be gnawing? must you be gnawing? must he be gnawing? must we be gnawing? must you be gnawing? must they be gnawing?
Perfect
must I have gnawed? must you have gnawed? must he have gnawed? must we have gnawed? must you have gnawed? must they have gnawed?
V-ing perfect
must I have been gnawing? must you have been gnawing? must he have been gnawing? must we have been gnawing? must you have been gnawing? must they have been gnawing?
Interro-negative form
Simple form
must I not gnaw? must you not gnaw? must he not gnaw? must we not gnaw? must you not gnaw? must they not gnaw?
V-ing form
must I not be gnawing? must you not be gnawing? must he not be gnawing? must we not be gnawing? must you not be gnawing? must they not be gnawing?
Perfect
must I not have gnawed? must you not have gnawed? must he not have gnawed? must we not have gnawed? must you not have gnawed? must they not have gnawed?
V-ing perfect
must I not have been gnawing? must you not have been gnawing? must he not have been gnawing? must we not have been gnawing? must you not have been gnawing? must they not have been gnawing?