Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I could ski ski you could ski ski he could ski ski we could ski ski you could ski ski they could ski ski
V-ing form
I could be ski skiing you could be ski skiing he could be ski skiing we could be ski skiing you could be ski skiing they could be ski skiing
Perfect
I could have ski skied you could have ski skied he could have ski skied we could have ski skied you could have ski skied they could have ski skied
V-ing perfect
I could have been ski skiing you could have been ski skiing he could have been ski skiing we could have been ski skiing you could have been ski skiing they could have been ski skiing
Negation
Simple form
I couldn't ski ski you couldn't ski ski he couldn't ski ski we couldn't ski ski you couldn't ski ski they couldn't ski ski
V-ing form
I couldn't be ski skiing you couldn't be ski skiing he couldn't be ski skiing we couldn't be ski skiing you couldn't be ski skiing they couldn't be ski skiing
Perfect
I couldn't have ski skied you couldn't have ski skied he couldn't have ski skied we couldn't have ski skied you couldn't have ski skied they couldn't have ski skied
V-ing perfect
I couldn't have been ski skiing you couldn't have been ski skiing he couldn't have been ski skiing we couldn't have been ski skiing you couldn't have been ski skiing they couldn't have been ski skiing
Interrogative form
Simple form
could I ski ski? could you ski ski? could he ski ski? could we ski ski? could you ski ski? could they ski ski?
V-ing form
could I be ski skiing? could you be ski skiing? could he be ski skiing? could we be ski skiing? could you be ski skiing? could they be ski skiing?
Perfect
could I have ski skied? could you have ski skied? could he have ski skied? could we have ski skied? could you have ski skied? could they have ski skied?
V-ing perfect
could I have been ski skiing? could you have been ski skiing? could he have been ski skiing? could we have been ski skiing? could you have been ski skiing? could they have been ski skiing?
Interro-negative form
Simple form
couldn't I ski ski? couldn't you ski ski? couldn't he ski ski? couldn't we ski ski? couldn't you ski ski? couldn't they ski ski?
V-ing form
couldn't I be ski skiing? couldn't you be ski skiing? couldn't he be ski skiing? couldn't we be ski skiing? couldn't you be ski skiing? couldn't they be ski skiing?
Perfect
couldn't I have ski skied? couldn't you have ski skied? couldn't he have ski skied? couldn't we have ski skied? couldn't you have ski skied? couldn't they have ski skied?
V-ing perfect
couldn't I have been ski skiing? couldn't you have been ski skiing? couldn't he have been ski skiing? couldn't we have been ski skiing? couldn't you have been ski skiing? couldn't they have been ski skiing?