I can demonstrate you can demonstrate he can demonstrate we can demonstrate you can demonstrate they can demonstrate
V-ing form
I can be demonstrating you can be demonstrating he can be demonstrating we can be demonstrating you can be demonstrating they can be demonstrating
Perfect
I can have demonstrated you can have demonstrated he can have demonstrated we can have demonstrated you can have demonstrated they can have demonstrated
V-ing perfect
I can have been demonstrating you can have been demonstrating he can have been demonstrating we can have been demonstrating you can have been demonstrating they can have been demonstrating
Negation
Simple form
I cannot demonstrate you cannot demonstrate he cannot demonstrate we cannot demonstrate you cannot demonstrate they cannot demonstrate
V-ing form
I cannot be demonstrating you cannot be demonstrating he cannot be demonstrating we cannot be demonstrating you cannot be demonstrating they cannot be demonstrating
Perfect
I cannot have demonstrated you cannot have demonstrated he cannot have demonstrated we cannot have demonstrated you cannot have demonstrated they cannot have demonstrated
V-ing perfect
I cannot have been demonstrating you cannot have been demonstrating he cannot have been demonstrating we cannot have been demonstrating you cannot have been demonstrating they cannot have been demonstrating
Interrogative form
Simple form
can I demonstrate? can you demonstrate? can he demonstrate? can we demonstrate? can you demonstrate? can they demonstrate?
V-ing form
can I be demonstrating? can you be demonstrating? can he be demonstrating? can we be demonstrating? can you be demonstrating? can they be demonstrating?
Perfect
can I have demonstrated? can you have demonstrated? can he have demonstrated? can we have demonstrated? can you have demonstrated? can they have demonstrated?
V-ing perfect
can I have been demonstrating? can you have been demonstrating? can he have been demonstrating? can we have been demonstrating? can you have been demonstrating? can they have been demonstrating?
Interro-negative form
Simple form
can I not demonstrate? can you not demonstrate? can he not demonstrate? can we not demonstrate? can you not demonstrate? can they not demonstrate?
V-ing form
can I not be demonstrating? can you not be demonstrating? can he not be demonstrating? can we not be demonstrating? can you not be demonstrating? can they not be demonstrating?
Perfect
can I not have demonstrated? can you not have demonstrated? can he not have demonstrated? can we not have demonstrated? can you not have demonstrated? can they not have demonstrated?
V-ing perfect
can I not have been demonstrating? can you not have been demonstrating? can he not have been demonstrating? can we not have been demonstrating? can you not have been demonstrating? can they not have been demonstrating?