I can checkmate you can checkmate he can checkmate we can checkmate you can checkmate they can checkmate
V-ing form
I can be checkmating you can be checkmating he can be checkmating we can be checkmating you can be checkmating they can be checkmating
Perfect
I can have checkmated you can have checkmated he can have checkmated we can have checkmated you can have checkmated they can have checkmated
V-ing perfect
I can have been checkmating you can have been checkmating he can have been checkmating we can have been checkmating you can have been checkmating they can have been checkmating
Negation
Simple form
I cannot checkmate you cannot checkmate he cannot checkmate we cannot checkmate you cannot checkmate they cannot checkmate
V-ing form
I cannot be checkmating you cannot be checkmating he cannot be checkmating we cannot be checkmating you cannot be checkmating they cannot be checkmating
Perfect
I cannot have checkmated you cannot have checkmated he cannot have checkmated we cannot have checkmated you cannot have checkmated they cannot have checkmated
V-ing perfect
I cannot have been checkmating you cannot have been checkmating he cannot have been checkmating we cannot have been checkmating you cannot have been checkmating they cannot have been checkmating
Interrogative form
Simple form
can I checkmate? can you checkmate? can he checkmate? can we checkmate? can you checkmate? can they checkmate?
V-ing form
can I be checkmating? can you be checkmating? can he be checkmating? can we be checkmating? can you be checkmating? can they be checkmating?
Perfect
can I have checkmated? can you have checkmated? can he have checkmated? can we have checkmated? can you have checkmated? can they have checkmated?
V-ing perfect
can I have been checkmating? can you have been checkmating? can he have been checkmating? can we have been checkmating? can you have been checkmating? can they have been checkmating?
Interro-negative form
Simple form
can I not checkmate? can you not checkmate? can he not checkmate? can we not checkmate? can you not checkmate? can they not checkmate?
V-ing form
can I not be checkmating? can you not be checkmating? can he not be checkmating? can we not be checkmating? can you not be checkmating? can they not be checkmating?
Perfect
can I not have checkmated? can you not have checkmated? can he not have checkmated? can we not have checkmated? can you not have checkmated? can they not have checkmated?
V-ing perfect
can I not have been checkmating? can you not have been checkmating? can he not have been checkmating? can we not have been checkmating? can you not have been checkmating? can they not have been checkmating?