must quack
Verbo regolare: quack - quacked- quacked

Affermazione 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
I must quack
you must quack
she must quack
we must quack
you must quack
they must quack 	I must be quacking
you must be quacking
she must be quacking
we must be quacking
you must be quacking
they must be quacking	I must have quacked
you must have quacked
she must have quacked
we must have quacked
you must have quacked
they must have quacked	I must have been quacking
you must have been quacking
she must have been quacking
we must have been quacking
you must have been quacking
they must have been quacking	

Negazione 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
I must not quack
you must not quack
she must not quack
we must not quack
you must not quack
they must not quack 	I must not be quacking
you must not be quacking
she must not be quacking
we must not be quacking
you must not be quacking
they must not be quacking	I must not have quacked
you must not have quacked
she must not have quacked
we must not have quacked
you must not have quacked
they must not have quacked	I must not have been quacking
you must not have been quacking
she must not have been quacking
we must not have been quacking
you must not have been quacking
they must not have been quacking	

Forma interrogativa 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
must I quack?
must you quack?
must she quack?
must we quack?
must you quack?
must they quack? 	must I be quacking?
must you be quacking?
must she be quacking?
must we be quacking?
must you be quacking?
must they be quacking? 	must I have quacked?
must you have quacked?
must she have quacked?
must we have quacked?
must you have quacked?
must they have quacked? 	must I have been quacking?
must you have been quacking?
must she have been quacking?
must we have been quacking?
must you have been quacking?
must they have been quacking? 	

Forma interro-negativa 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
must I not quack?
must you not quack?
must she not quack?
must we not quack?
must you not quack?
must they not quack? 	must I not be quacking?
must you not be quacking?
must she not be quacking?
must we not be quacking?
must you not be quacking?
must they not be quacking? 	must I not have quacked?
must you not have quacked?
must she not have quacked?
must we not have quacked?
must you not have quacked?
must they not have quacked? 	must I not have been quacking?
must you not have been quacking?
must she not have been quacking?
must we not have been quacking?
must you not have been quacking?
must they not have been quacking?