I could crash you could crash he could crash we could crash you could crash they could crash
V-ing form
I could be crashing you could be crashing he could be crashing we could be crashing you could be crashing they could be crashing
Perfect
I could have crashed you could have crashed he could have crashed we could have crashed you could have crashed they could have crashed
V-ing perfect
I could have been crashing you could have been crashing he could have been crashing we could have been crashing you could have been crashing they could have been crashing
Negation
Simple form
I could not crash you could not crash he could not crash we could not crash you could not crash they could not crash
V-ing form
I could not be crashing you could not be crashing he could not be crashing we could not be crashing you could not be crashing they could not be crashing
Perfect
I could not have crashed you could not have crashed he could not have crashed we could not have crashed you could not have crashed they could not have crashed
V-ing perfect
I could not have been crashing you could not have been crashing he could not have been crashing we could not have been crashing you could not have been crashing they could not have been crashing
Interrogative form
Simple form
could I crash? could you crash? could he crash? could we crash? could you crash? could they crash?
V-ing form
could I be crashing? could you be crashing? could he be crashing? could we be crashing? could you be crashing? could they be crashing?
Perfect
could I have crashed? could you have crashed? could he have crashed? could we have crashed? could you have crashed? could they have crashed?
V-ing perfect
could I have been crashing? could you have been crashing? could he have been crashing? could we have been crashing? could you have been crashing? could they have been crashing?
Interro-negative form
Simple form
could I not crash? could you not crash? could he not crash? could we not crash? could you not crash? could they not crash?
V-ing form
could I not be crashing? could you not be crashing? could he not be crashing? could we not be crashing? could you not be crashing? could they not be crashing?
Perfect
could I not have crashed? could you not have crashed? could he not have crashed? could we not have crashed? could you not have crashed? could they not have crashed?
V-ing perfect
could I not have been crashing? could you not have been crashing? could he not have been crashing? could we not have been crashing? could you not have been crashing? could they not have been crashing?