must ground
Verbo regular: ground - grounded- grounded

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I must ground
you must ground
he must ground
we must ground
you must ground
they must ground 	I must be grounding
you must be grounding
he must be grounding
we must be grounding
you must be grounding
they must be grounding	I must have grounded
you must have grounded
he must have grounded
we must have grounded
you must have grounded
they must have grounded	I must have been grounding
you must have been grounding
he must have been grounding
we must have been grounding
you must have been grounding
they must have been grounding	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I mustn't ground
you mustn't ground
he mustn't ground
we mustn't ground
you mustn't ground
they mustn't ground 	I mustn't be grounding
you mustn't be grounding
he mustn't be grounding
we mustn't be grounding
you mustn't be grounding
they mustn't be grounding	I mustn't have grounded
you mustn't have grounded
he mustn't have grounded
we mustn't have grounded
you mustn't have grounded
they mustn't have grounded	I mustn't have been grounding
you mustn't have been grounding
he mustn't have been grounding
we mustn't have been grounding
you mustn't have been grounding
they mustn't have been grounding	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
must I ground?
must you ground?
must he ground?
must we ground?
must you ground?
must they ground? 	must I be grounding?
must you be grounding?
must he be grounding?
must we be grounding?
must you be grounding?
must they be grounding? 	must I have grounded?
must you have grounded?
must he have grounded?
must we have grounded?
must you have grounded?
must they have grounded? 	must I have been grounding?
must you have been grounding?
must he have been grounding?
must we have been grounding?
must you have been grounding?
must they have been grounding? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
mustn't I ground?
mustn't you ground?
mustn't he ground?
mustn't we ground?
mustn't you ground?
mustn't they ground? 	mustn't I be grounding?
mustn't you be grounding?
mustn't he be grounding?
mustn't we be grounding?
mustn't you be grounding?
mustn't they be grounding? 	mustn't I have grounded?
mustn't you have grounded?
mustn't he have grounded?
mustn't we have grounded?
mustn't you have grounded?
mustn't they have grounded? 	mustn't I have been grounding?
mustn't you have been grounding?
mustn't he have been grounding?
mustn't we have been grounding?
mustn't you have been grounding?
mustn't they have been grounding?