I can decay you can decay she can decay we can decay you can decay they can decay
V-ing form
I can be decaying you can be decaying she can be decaying we can be decaying you can be decaying they can be decaying
Perfect
I can have decayed you can have decayed she can have decayed we can have decayed you can have decayed they can have decayed
V-ing perfect
I can have been decaying you can have been decaying she can have been decaying we can have been decaying you can have been decaying they can have been decaying
Negation
Simple form
I cannot decay you cannot decay she cannot decay we cannot decay you cannot decay they cannot decay
V-ing form
I cannot be decaying you cannot be decaying she cannot be decaying we cannot be decaying you cannot be decaying they cannot be decaying
Perfect
I cannot have decayed you cannot have decayed she cannot have decayed we cannot have decayed you cannot have decayed they cannot have decayed
V-ing perfect
I cannot have been decaying you cannot have been decaying she cannot have been decaying we cannot have been decaying you cannot have been decaying they cannot have been decaying
Interrogative form
Simple form
can I decay? can you decay? can she decay? can we decay? can you decay? can they decay?
V-ing form
can I be decaying? can you be decaying? can she be decaying? can we be decaying? can you be decaying? can they be decaying?
Perfect
can I have decayed? can you have decayed? can she have decayed? can we have decayed? can you have decayed? can they have decayed?
V-ing perfect
can I have been decaying? can you have been decaying? can she have been decaying? can we have been decaying? can you have been decaying? can they have been decaying?
Interro-negative form
Simple form
can I not decay? can you not decay? can she not decay? can we not decay? can you not decay? can they not decay?
V-ing form
can I not be decaying? can you not be decaying? can she not be decaying? can we not be decaying? can you not be decaying? can they not be decaying?
Perfect
can I not have decayed? can you not have decayed? can she not have decayed? can we not have decayed? can you not have decayed? can they not have decayed?
V-ing perfect
can I not have been decaying? can you not have been decaying? can she not have been decaying? can we not have been decaying? can you not have been decaying? can they not have been decaying?