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 could not whiff you could not whiff he could not whiff we could not whiff you could not whiff they could not whiff	I could not be whiffing you could not be whiffing he could not be whiffing we could not be whiffing you could not be whiffing they could not be whiffing
Perfect	V-ing perfect
I could not have whiffed you could not have whiffed he could not have whiffed we could not have whiffed you could not have whiffed they could not have whiffed	I could not have been whiffing you could not have been whiffing he could not have been whiffing we could not have been whiffing you could not have been whiffing they could not 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
could I not whiff? could you not whiff? could he not whiff? could we not whiff? could you not whiff? could they not whiff?	could I not be whiffing? could you not be whiffing? could he not be whiffing? could we not be whiffing? could you not be whiffing? could they not be whiffing?
Perfect	V-ing perfect
could I not have whiffed? could you not have whiffed? could he not have whiffed? could we not have whiffed? could you not have whiffed? could they not have whiffed?	could I not have been whiffing? could you not have been whiffing? could he not have been whiffing? could we not have been whiffing? could you not have been whiffing? could they not have been whiffing?