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