Warning, this verb may not exist. Conjugation is given as example.
Affirmation
Simple form
I could fall. stumbel you could fall. stumbel he could fall. stumbel we could fall. stumbel you could fall. stumbel they could fall. stumbel
V-ing form
I could be fall. stumbeling you could be fall. stumbeling he could be fall. stumbeling we could be fall. stumbeling you could be fall. stumbeling they could be fall. stumbeling
Perfect
I could have fall. stumbeled you could have fall. stumbeled he could have fall. stumbeled we could have fall. stumbeled you could have fall. stumbeled they could have fall. stumbeled
V-ing perfect
I could have been fall. stumbeling you could have been fall. stumbeling he could have been fall. stumbeling we could have been fall. stumbeling you could have been fall. stumbeling they could have been fall. stumbeling
Negation
Simple form
I could not fall. stumbel you could not fall. stumbel he could not fall. stumbel we could not fall. stumbel you could not fall. stumbel they could not fall. stumbel
V-ing form
I could not be fall. stumbeling you could not be fall. stumbeling he could not be fall. stumbeling we could not be fall. stumbeling you could not be fall. stumbeling they could not be fall. stumbeling
Perfect
I could not have fall. stumbeled you could not have fall. stumbeled he could not have fall. stumbeled we could not have fall. stumbeled you could not have fall. stumbeled they could not have fall. stumbeled
V-ing perfect
I could not have been fall. stumbeling you could not have been fall. stumbeling he could not have been fall. stumbeling we could not have been fall. stumbeling you could not have been fall. stumbeling they could not have been fall. stumbeling
Interrogative form
Simple form
could I fall. stumbel? could you fall. stumbel? could he fall. stumbel? could we fall. stumbel? could you fall. stumbel? could they fall. stumbel?
V-ing form
could I be fall. stumbeling? could you be fall. stumbeling? could he be fall. stumbeling? could we be fall. stumbeling? could you be fall. stumbeling? could they be fall. stumbeling?
Perfect
could I have fall. stumbeled? could you have fall. stumbeled? could he have fall. stumbeled? could we have fall. stumbeled? could you have fall. stumbeled? could they have fall. stumbeled?
V-ing perfect
could I have been fall. stumbeling? could you have been fall. stumbeling? could he have been fall. stumbeling? could we have been fall. stumbeling? could you have been fall. stumbeling? could they have been fall. stumbeling?
Interro-negative form
Simple form
could I not fall. stumbel? could you not fall. stumbel? could he not fall. stumbel? could we not fall. stumbel? could you not fall. stumbel? could they not fall. stumbel?
V-ing form
could I not be fall. stumbeling? could you not be fall. stumbeling? could he not be fall. stumbeling? could we not be fall. stumbeling? could you not be fall. stumbeling? could they not be fall. stumbeling?
Perfect
could I not have fall. stumbeled? could you not have fall. stumbeled? could he not have fall. stumbeled? could we not have fall. stumbeled? could you not have fall. stumbeled? could they not have fall. stumbeled?
V-ing perfect
could I not have been fall. stumbeling? could you not have been fall. stumbeling? could he not have been fall. stumbeling? could we not have been fall. stumbeling? could you not have been fall. stumbeling? could they not have been fall. stumbeling?