English verb conjugation
COULD MUFF

Regular verb: muff - muffed - muffed

Affirmation

Simple form	V-ing form
I could muff you could muff he could muff we could muff you could muff they could muff	I could be muffing you could be muffing he could be muffing we could be muffing you could be muffing they could be muffing
Perfect	V-ing perfect
I could have muffed you could have muffed he could have muffed we could have muffed you could have muffed they could have muffed	I could have been muffing you could have been muffing he could have been muffing we could have been muffing you could have been muffing they could have been muffing

Negation

Simple form	V-ing form
I couldn't muff you couldn't muff he couldn't muff we couldn't muff you couldn't muff they couldn't muff	I couldn't be muffing you couldn't be muffing he couldn't be muffing we couldn't be muffing you couldn't be muffing they couldn't be muffing
Perfect	V-ing perfect
I couldn't have muffed you couldn't have muffed he couldn't have muffed we couldn't have muffed you couldn't have muffed they couldn't have muffed	I couldn't have been muffing you couldn't have been muffing he couldn't have been muffing we couldn't have been muffing you couldn't have been muffing they couldn't have been muffing

Interrogative form

Simple form	V-ing form
could I muff? could you muff? could he muff? could we muff? could you muff? could they muff?	could I be muffing? could you be muffing? could he be muffing? could we be muffing? could you be muffing? could they be muffing?
Perfect	V-ing perfect
could I have muffed? could you have muffed? could he have muffed? could we have muffed? could you have muffed? could they have muffed?	could I have been muffing? could you have been muffing? could he have been muffing? could we have been muffing? could you have been muffing? could they have been muffing?

Interro-negative form

Simple form	V-ing form
couldn't I muff? couldn't you muff? couldn't he muff? couldn't we muff? couldn't you muff? couldn't they muff?	couldn't I be muffing? couldn't you be muffing? couldn't he be muffing? couldn't we be muffing? couldn't you be muffing? couldn't they be muffing?
Perfect	V-ing perfect
couldn't I have muffed? couldn't you have muffed? couldn't he have muffed? couldn't we have muffed? couldn't you have muffed? couldn't they have muffed?	couldn't I have been muffing? couldn't you have been muffing? couldn't he have been muffing? couldn't we have been muffing? couldn't you have been muffing? couldn't they have been muffing?