must flatten
Verbo regular: flatten - flattened- flattened

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must flatten
you must flatten
he must flatten
we must flatten
you must flatten
they must flatten 	I must be flattening
you must be flattening
he must be flattening
we must be flattening
you must be flattening
they must be flattening	I must have flattened
you must have flattened
he must have flattened
we must have flattened
you must have flattened
they must have flattened	I must have been flattening
you must have been flattening
he must have been flattening
we must have been flattening
you must have been flattening
they must have been flattening	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must not flatten
you must not flatten
he must not flatten
we must not flatten
you must not flatten
they must not flatten 	I must not be flattening
you must not be flattening
he must not be flattening
we must not be flattening
you must not be flattening
they must not be flattening	I must not have flattened
you must not have flattened
he must not have flattened
we must not have flattened
you must not have flattened
they must not have flattened	I must not have been flattening
you must not have been flattening
he must not have been flattening
we must not have been flattening
you must not have been flattening
they must not have been flattening	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I flatten?
must you flatten?
must he flatten?
must we flatten?
must you flatten?
must they flatten? 	must I be flattening?
must you be flattening?
must he be flattening?
must we be flattening?
must you be flattening?
must they be flattening? 	must I have flattened?
must you have flattened?
must he have flattened?
must we have flattened?
must you have flattened?
must they have flattened? 	must I have been flattening?
must you have been flattening?
must he have been flattening?
must we have been flattening?
must you have been flattening?
must they have been flattening? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I not flatten?
must you not flatten?
must he not flatten?
must we not flatten?
must you not flatten?
must they not flatten? 	must I not be flattening?
must you not be flattening?
must he not be flattening?
must we not be flattening?
must you not be flattening?
must they not be flattening? 	must I not have flattened?
must you not have flattened?
must he not have flattened?
must we not have flattened?
must you not have flattened?
must they not have flattened? 	must I not have been flattening?
must you not have been flattening?
must he not have been flattening?
must we not have been flattening?
must you not have been flattening?
must they not have been flattening?