English verb conjugation
COULD WINDSURF

Regular verb: windsurf - windsurfed - windsurfed

Affirmation

Simple form	V-ing form
I could windsurf you could windsurf he could windsurf we could windsurf you could windsurf they could windsurf	I could be windsurfing you could be windsurfing he could be windsurfing we could be windsurfing you could be windsurfing they could be windsurfing
Perfect	V-ing perfect
I could have windsurfed you could have windsurfed he could have windsurfed we could have windsurfed you could have windsurfed they could have windsurfed	I could have been windsurfing you could have been windsurfing he could have been windsurfing we could have been windsurfing you could have been windsurfing they could have been windsurfing

Negation

Simple form	V-ing form
I couldn't windsurf you couldn't windsurf he couldn't windsurf we couldn't windsurf you couldn't windsurf they couldn't windsurf	I couldn't be windsurfing you couldn't be windsurfing he couldn't be windsurfing we couldn't be windsurfing you couldn't be windsurfing they couldn't be windsurfing
Perfect	V-ing perfect
I couldn't have windsurfed you couldn't have windsurfed he couldn't have windsurfed we couldn't have windsurfed you couldn't have windsurfed they couldn't have windsurfed	I couldn't have been windsurfing you couldn't have been windsurfing he couldn't have been windsurfing we couldn't have been windsurfing you couldn't have been windsurfing they couldn't have been windsurfing

Interrogative form

Simple form	V-ing form
could I windsurf? could you windsurf? could he windsurf? could we windsurf? could you windsurf? could they windsurf?	could I be windsurfing? could you be windsurfing? could he be windsurfing? could we be windsurfing? could you be windsurfing? could they be windsurfing?
Perfect	V-ing perfect
could I have windsurfed? could you have windsurfed? could he have windsurfed? could we have windsurfed? could you have windsurfed? could they have windsurfed?	could I have been windsurfing? could you have been windsurfing? could he have been windsurfing? could we have been windsurfing? could you have been windsurfing? could they have been windsurfing?

Interro-negative form

Simple form	V-ing form
couldn't I windsurf? couldn't you windsurf? couldn't he windsurf? couldn't we windsurf? couldn't you windsurf? couldn't they windsurf?	couldn't I be windsurfing? couldn't you be windsurfing? couldn't he be windsurfing? couldn't we be windsurfing? couldn't you be windsurfing? couldn't they be windsurfing?
Perfect	V-ing perfect
couldn't I have windsurfed? couldn't you have windsurfed? couldn't he have windsurfed? couldn't we have windsurfed? couldn't you have windsurfed? couldn't they have windsurfed?	couldn't I have been windsurfing? couldn't you have been windsurfing? couldn't he have been windsurfing? couldn't we have been windsurfing? couldn't you have been windsurfing? couldn't they have been windsurfing?