must grain
Verbo regular: grain - grained- grained

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must grain
you must grain
he must grain
we must grain
you must grain
they must grain 	I must be graining
you must be graining
he must be graining
we must be graining
you must be graining
they must be graining	I must have grained
you must have grained
he must have grained
we must have grained
you must have grained
they must have grained	I must have been graining
you must have been graining
he must have been graining
we must have been graining
you must have been graining
they must have been graining	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not grain
you must not grain
he must not grain
we must not grain
you must not grain
they must not grain 	I must not be graining
you must not be graining
he must not be graining
we must not be graining
you must not be graining
they must not be graining	I must not have grained
you must not have grained
he must not have grained
we must not have grained
you must not have grained
they must not have grained	I must not have been graining
you must not have been graining
he must not have been graining
we must not have been graining
you must not have been graining
they must not have been graining	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I grain?
must you grain?
must he grain?
must we grain?
must you grain?
must they grain? 	must I be graining?
must you be graining?
must he be graining?
must we be graining?
must you be graining?
must they be graining? 	must I have grained?
must you have grained?
must he have grained?
must we have grained?
must you have grained?
must they have grained? 	must I have been graining?
must you have been graining?
must he have been graining?
must we have been graining?
must you have been graining?
must they have been graining? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not grain?
must you not grain?
must he not grain?
must we not grain?
must you not grain?
must they not grain? 	must I not be graining?
must you not be graining?
must he not be graining?
must we not be graining?
must you not be graining?
must they not be graining? 	must I not have grained?
must you not have grained?
must he not have grained?
must we not have grained?
must you not have grained?
must they not have grained? 	must I not have been graining?
must you not have been graining?
must he not have been graining?
must we not have been graining?
must you not have been graining?
must they not have been graining?