can grumble
Regular verb: grumble - grumbled- grumbled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can grumble
you can grumble
she can grumble
we can grumble
you can grumble
they can grumble 	I can be grumbling
you can be grumbling
she can be grumbling
we can be grumbling
you can be grumbling
they can be grumbling	I can have grumbled
you can have grumbled
she can have grumbled
we can have grumbled
you can have grumbled
they can have grumbled	I can have been grumbling
you can have been grumbling
she can have been grumbling
we can have been grumbling
you can have been grumbling
they can have been grumbling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can't grumble
you can't grumble
she can't grumble
we can't grumble
you can't grumble
they can't grumble 	I can't be grumbling
you can't be grumbling
she can't be grumbling
we can't be grumbling
you can't be grumbling
they can't be grumbling	I can't have grumbled
you can't have grumbled
she can't have grumbled
we can't have grumbled
you can't have grumbled
they can't have grumbled	I can't have been grumbling
you can't have been grumbling
she can't have been grumbling
we can't have been grumbling
you can't have been grumbling
they can't have been grumbling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can I grumble?
can you grumble?
can she grumble?
can we grumble?
can you grumble?
can they grumble? 	can I be grumbling?
can you be grumbling?
can she be grumbling?
can we be grumbling?
can you be grumbling?
can they be grumbling? 	can I have grumbled?
can you have grumbled?
can she have grumbled?
can we have grumbled?
can you have grumbled?
can they have grumbled? 	can I have been grumbling?
can you have been grumbling?
can she have been grumbling?
can we have been grumbling?
can you have been grumbling?
can they have been grumbling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
can't I grumble?
can't you grumble?
can't she grumble?
can't we grumble?
can't you grumble?
can't they grumble? 	can't I be grumbling?
can't you be grumbling?
can't she be grumbling?
can't we be grumbling?
can't you be grumbling?
can't they be grumbling? 	can't I have grumbled?
can't you have grumbled?
can't she have grumbled?
can't we have grumbled?
can't you have grumbled?
can't they have grumbled? 	can't I have been grumbling?
can't you have been grumbling?
can't she have been grumbling?
can't we have been grumbling?
can't you have been grumbling?
can't they have been grumbling?