I can fever you can fever she can fever we can fever you can fever they can fever
V-ing form
I can be fevering you can be fevering she can be fevering we can be fevering you can be fevering they can be fevering
Perfect
I can have fevered you can have fevered she can have fevered we can have fevered you can have fevered they can have fevered
V-ing perfect
I can have been fevering you can have been fevering she can have been fevering we can have been fevering you can have been fevering they can have been fevering
Negation
Simple form
I cannot fever you cannot fever she cannot fever we cannot fever you cannot fever they cannot fever
V-ing form
I cannot be fevering you cannot be fevering she cannot be fevering we cannot be fevering you cannot be fevering they cannot be fevering
Perfect
I cannot have fevered you cannot have fevered she cannot have fevered we cannot have fevered you cannot have fevered they cannot have fevered
V-ing perfect
I cannot have been fevering you cannot have been fevering she cannot have been fevering we cannot have been fevering you cannot have been fevering they cannot have been fevering
Interrogative form
Simple form
can I fever? can you fever? can she fever? can we fever? can you fever? can they fever?
V-ing form
can I be fevering? can you be fevering? can she be fevering? can we be fevering? can you be fevering? can they be fevering?
Perfect
can I have fevered? can you have fevered? can she have fevered? can we have fevered? can you have fevered? can they have fevered?
V-ing perfect
can I have been fevering? can you have been fevering? can she have been fevering? can we have been fevering? can you have been fevering? can they have been fevering?
Interro-negative form
Simple form
can I not fever? can you not fever? can she not fever? can we not fever? can you not fever? can they not fever?
V-ing form
can I not be fevering? can you not be fevering? can she not be fevering? can we not be fevering? can you not be fevering? can they not be fevering?
Perfect
can I not have fevered? can you not have fevered? can she not have fevered? can we not have fevered? can you not have fevered? can they not have fevered?
V-ing perfect
can I not have been fevering? can you not have been fevering? can she not have been fevering? can we not have been fevering? can you not have been fevering? can they not have been fevering?