I must rat you must rat she must rat we must rat you must rat they must rat
V-ing form
I must be ratting you must be ratting she must be ratting we must be ratting you must be ratting they must be ratting
Perfect
I must have ratted you must have ratted she must have ratted we must have ratted you must have ratted they must have ratted
V-ing perfect
I must have been ratting you must have been ratting she must have been ratting we must have been ratting you must have been ratting they must have been ratting
Negation
Simple form
I must not rat you must not rat she must not rat we must not rat you must not rat they must not rat
V-ing form
I must not be ratting you must not be ratting she must not be ratting we must not be ratting you must not be ratting they must not be ratting
Perfect
I must not have ratted you must not have ratted she must not have ratted we must not have ratted you must not have ratted they must not have ratted
V-ing perfect
I must not have been ratting you must not have been ratting she must not have been ratting we must not have been ratting you must not have been ratting they must not have been ratting
Interrogative form
Simple form
must I rat? must you rat? must she rat? must we rat? must you rat? must they rat?
V-ing form
must I be ratting? must you be ratting? must she be ratting? must we be ratting? must you be ratting? must they be ratting?
Perfect
must I have ratted? must you have ratted? must she have ratted? must we have ratted? must you have ratted? must they have ratted?
V-ing perfect
must I have been ratting? must you have been ratting? must she have been ratting? must we have been ratting? must you have been ratting? must they have been ratting?
Interro-negative form
Simple form
must I not rat? must you not rat? must she not rat? must we not rat? must you not rat? must they not rat?
V-ing form
must I not be ratting? must you not be ratting? must she not be ratting? must we not be ratting? must you not be ratting? must they not be ratting?
Perfect
must I not have ratted? must you not have ratted? must she not have ratted? must we not have ratted? must you not have ratted? must they not have ratted?
V-ing perfect
must I not have been ratting? must you not have been ratting? must she not have been ratting? must we not have been ratting? must you not have been ratting? must they not have been ratting?