English verb conjugation
COULD WHIFF

Regular verb: whiff - whiffed - whiffed

Affirmation

Simple form	V-ing form
I could whiff you could whiff he could whiff we could whiff you could whiff they could whiff	I could be whiffing you could be whiffing he could be whiffing we could be whiffing you could be whiffing they could be whiffing
Perfect	V-ing perfect
I could have whiffed you could have whiffed he could have whiffed we could have whiffed you could have whiffed they could have whiffed	I could have been whiffing you could have been whiffing he could have been whiffing we could have been whiffing you could have been whiffing they could have been whiffing

Negation

Simple form	V-ing form
I couldn't whiff you couldn't whiff he couldn't whiff we couldn't whiff you couldn't whiff they couldn't whiff	I couldn't be whiffing you couldn't be whiffing he couldn't be whiffing we couldn't be whiffing you couldn't be whiffing they couldn't be whiffing
Perfect	V-ing perfect
I couldn't have whiffed you couldn't have whiffed he couldn't have whiffed we couldn't have whiffed you couldn't have whiffed they couldn't have whiffed	I couldn't have been whiffing you couldn't have been whiffing he couldn't have been whiffing we couldn't have been whiffing you couldn't have been whiffing they couldn't have been whiffing

Interrogative form

Simple form	V-ing form
could I whiff? could you whiff? could he whiff? could we whiff? could you whiff? could they whiff?	could I be whiffing? could you be whiffing? could he be whiffing? could we be whiffing? could you be whiffing? could they be whiffing?
Perfect	V-ing perfect
could I have whiffed? could you have whiffed? could he have whiffed? could we have whiffed? could you have whiffed? could they have whiffed?	could I have been whiffing? could you have been whiffing? could he have been whiffing? could we have been whiffing? could you have been whiffing? could they have been whiffing?

Interro-negative form

Simple form	V-ing form
couldn't I whiff? couldn't you whiff? couldn't he whiff? couldn't we whiff? couldn't you whiff? couldn't they whiff?	couldn't I be whiffing? couldn't you be whiffing? couldn't he be whiffing? couldn't we be whiffing? couldn't you be whiffing? couldn't they be whiffing?
Perfect	V-ing perfect
couldn't I have whiffed? couldn't you have whiffed? couldn't he have whiffed? couldn't we have whiffed? couldn't you have whiffed? couldn't they have whiffed?	couldn't I have been whiffing? couldn't you have been whiffing? couldn't he have been whiffing? couldn't we have been whiffing? couldn't you have been whiffing? couldn't they have been whiffing?