English verb conjugation
CAN GRUMBLE

Regular verb: grumble - grumbled - grumbled

Affirmation

Simple form	V-ing form
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
Perfect	V-ing perfect
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
I cannot grumble you cannot grumble she cannot grumble we cannot grumble you cannot grumble they cannot grumble	I cannot be grumbling you cannot be grumbling she cannot be grumbling we cannot be grumbling you cannot be grumbling they cannot be grumbling
Perfect	V-ing perfect
I cannot have grumbled you cannot have grumbled she cannot have grumbled we cannot have grumbled you cannot have grumbled they cannot have grumbled	I cannot have been grumbling you cannot have been grumbling she cannot have been grumbling we cannot have been grumbling you cannot have been grumbling they cannot have been grumbling

Interrogative form

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