could muffle
Regular verb: muffle - muffled- muffled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could muffle
you could muffle
she could muffle
we could muffle
you could muffle
they could muffle 	I could be muffling
you could be muffling
she could be muffling
we could be muffling
you could be muffling
they could be muffling	I could have muffled
you could have muffled
she could have muffled
we could have muffled
you could have muffled
they could have muffled	I could have been muffling
you could have been muffling
she could have been muffling
we could have been muffling
you could have been muffling
they could have been muffling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't muffle
you couldn't muffle
she couldn't muffle
we couldn't muffle
you couldn't muffle
they couldn't muffle 	I couldn't be muffling
you couldn't be muffling
she couldn't be muffling
we couldn't be muffling
you couldn't be muffling
they couldn't be muffling	I couldn't have muffled
you couldn't have muffled
she couldn't have muffled
we couldn't have muffled
you couldn't have muffled
they couldn't have muffled	I couldn't have been muffling
you couldn't have been muffling
she couldn't have been muffling
we couldn't have been muffling
you couldn't have been muffling
they couldn't have been muffling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I muffle?
could you muffle?
could she muffle?
could we muffle?
could you muffle?
could they muffle? 	could I be muffling?
could you be muffling?
could she be muffling?
could we be muffling?
could you be muffling?
could they be muffling? 	could I have muffled?
could you have muffled?
could she have muffled?
could we have muffled?
could you have muffled?
could they have muffled? 	could I have been muffling?
could you have been muffling?
could she have been muffling?
could we have been muffling?
could you have been muffling?
could they have been muffling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I muffle?
couldn't you muffle?
couldn't she muffle?
couldn't we muffle?
couldn't you muffle?
couldn't they muffle? 	couldn't I be muffling?
couldn't you be muffling?
couldn't she be muffling?
couldn't we be muffling?
couldn't you be muffling?
couldn't they be muffling? 	couldn't I have muffled?
couldn't you have muffled?
couldn't she have muffled?
couldn't we have muffled?
couldn't you have muffled?
couldn't they have muffled? 	couldn't I have been muffling?
couldn't you have been muffling?
couldn't she have been muffling?
couldn't we have been muffling?
couldn't you have been muffling?
couldn't they have been muffling?