I can commemorate you can commemorate she can commemorate we can commemorate you can commemorate they can commemorate
V-ing form
I can be commemorating you can be commemorating she can be commemorating we can be commemorating you can be commemorating they can be commemorating
Perfect
I can have commemorated you can have commemorated she can have commemorated we can have commemorated you can have commemorated they can have commemorated
V-ing perfect
I can have been commemorating you can have been commemorating she can have been commemorating we can have been commemorating you can have been commemorating they can have been commemorating
Negation
Simple form
I cannot commemorate you cannot commemorate she cannot commemorate we cannot commemorate you cannot commemorate they cannot commemorate
V-ing form
I cannot be commemorating you cannot be commemorating she cannot be commemorating we cannot be commemorating you cannot be commemorating they cannot be commemorating
Perfect
I cannot have commemorated you cannot have commemorated she cannot have commemorated we cannot have commemorated you cannot have commemorated they cannot have commemorated
V-ing perfect
I cannot have been commemorating you cannot have been commemorating she cannot have been commemorating we cannot have been commemorating you cannot have been commemorating they cannot have been commemorating
Interrogative form
Simple form
can I commemorate? can you commemorate? can she commemorate? can we commemorate? can you commemorate? can they commemorate?
V-ing form
can I be commemorating? can you be commemorating? can she be commemorating? can we be commemorating? can you be commemorating? can they be commemorating?
Perfect
can I have commemorated? can you have commemorated? can she have commemorated? can we have commemorated? can you have commemorated? can they have commemorated?
V-ing perfect
can I have been commemorating? can you have been commemorating? can she have been commemorating? can we have been commemorating? can you have been commemorating? can they have been commemorating?
Interro-negative form
Simple form
can I not commemorate? can you not commemorate? can she not commemorate? can we not commemorate? can you not commemorate? can they not commemorate?
V-ing form
can I not be commemorating? can you not be commemorating? can she not be commemorating? can we not be commemorating? can you not be commemorating? can they not be commemorating?
Perfect
can I not have commemorated? can you not have commemorated? can she not have commemorated? can we not have commemorated? can you not have commemorated? can they not have commemorated?
V-ing perfect
can I not have been commemorating? can you not have been commemorating? can she not have been commemorating? can we not have been commemorating? can you not have been commemorating? can they not have been commemorating?