I can discard you can discard she can discard we can discard you can discard they can discard
V-ing form
I can be discarding you can be discarding she can be discarding we can be discarding you can be discarding they can be discarding
Perfect
I can have discarded you can have discarded she can have discarded we can have discarded you can have discarded they can have discarded
V-ing perfect
I can have been discarding you can have been discarding she can have been discarding we can have been discarding you can have been discarding they can have been discarding
Negation
Simple form
I cannot discard you cannot discard she cannot discard we cannot discard you cannot discard they cannot discard
V-ing form
I cannot be discarding you cannot be discarding she cannot be discarding we cannot be discarding you cannot be discarding they cannot be discarding
Perfect
I cannot have discarded you cannot have discarded she cannot have discarded we cannot have discarded you cannot have discarded they cannot have discarded
V-ing perfect
I cannot have been discarding you cannot have been discarding she cannot have been discarding we cannot have been discarding you cannot have been discarding they cannot have been discarding
Interrogative form
Simple form
can I discard? can you discard? can she discard? can we discard? can you discard? can they discard?
V-ing form
can I be discarding? can you be discarding? can she be discarding? can we be discarding? can you be discarding? can they be discarding?
Perfect
can I have discarded? can you have discarded? can she have discarded? can we have discarded? can you have discarded? can they have discarded?
V-ing perfect
can I have been discarding? can you have been discarding? can she have been discarding? can we have been discarding? can you have been discarding? can they have been discarding?
Interro-negative form
Simple form
can I not discard? can you not discard? can she not discard? can we not discard? can you not discard? can they not discard?
V-ing form
can I not be discarding? can you not be discarding? can she not be discarding? can we not be discarding? can you not be discarding? can they not be discarding?
Perfect
can I not have discarded? can you not have discarded? can she not have discarded? can we not have discarded? can you not have discarded? can they not have discarded?
V-ing perfect
can I not have been discarding? can you not have been discarding? can she not have been discarding? can we not have been discarding? can you not have been discarding? can they not have been discarding?