I must pet you must pet he must pet we must pet you must pet they must pet
V-ing form
I must be petting you must be petting he must be petting we must be petting you must be petting they must be petting
Perfect
I must have petted you must have petted he must have petted we must have petted you must have petted they must have petted
V-ing perfect
I must have been petting you must have been petting he must have been petting we must have been petting you must have been petting they must have been petting
Negation
Simple form
I must not pet you must not pet he must not pet we must not pet you must not pet they must not pet
V-ing form
I must not be petting you must not be petting he must not be petting we must not be petting you must not be petting they must not be petting
Perfect
I must not have petted you must not have petted he must not have petted we must not have petted you must not have petted they must not have petted
V-ing perfect
I must not have been petting you must not have been petting he must not have been petting we must not have been petting you must not have been petting they must not have been petting
Interrogative form
Simple form
must I pet? must you pet? must he pet? must we pet? must you pet? must they pet?
V-ing form
must I be petting? must you be petting? must he be petting? must we be petting? must you be petting? must they be petting?
Perfect
must I have petted? must you have petted? must he have petted? must we have petted? must you have petted? must they have petted?
V-ing perfect
must I have been petting? must you have been petting? must he have been petting? must we have been petting? must you have been petting? must they have been petting?
Interro-negative form
Simple form
must I not pet? must you not pet? must he not pet? must we not pet? must you not pet? must they not pet?
V-ing form
must I not be petting? must you not be petting? must he not be petting? must we not be petting? must you not be petting? must they not be petting?
Perfect
must I not have petted? must you not have petted? must he not have petted? must we not have petted? must you not have petted? must they not have petted?
V-ing perfect
must I not have been petting? must you not have been petting? must he not have been petting? must we not have been petting? must you not have been petting? must they not have been petting?