I can understeer you can understeer she can understeer we can understeer you can understeer they can understeer
V-ing form
I can be understeering you can be understeering she can be understeering we can be understeering you can be understeering they can be understeering
Perfect
I can have understeered you can have understeered she can have understeered we can have understeered you can have understeered they can have understeered
V-ing perfect
I can have been understeering you can have been understeering she can have been understeering we can have been understeering you can have been understeering they can have been understeering
Negation
Simple form
I cannot understeer you cannot understeer she cannot understeer we cannot understeer you cannot understeer they cannot understeer
V-ing form
I cannot be understeering you cannot be understeering she cannot be understeering we cannot be understeering you cannot be understeering they cannot be understeering
Perfect
I cannot have understeered you cannot have understeered she cannot have understeered we cannot have understeered you cannot have understeered they cannot have understeered
V-ing perfect
I cannot have been understeering you cannot have been understeering she cannot have been understeering we cannot have been understeering you cannot have been understeering they cannot have been understeering
Interrogative form
Simple form
can I understeer? can you understeer? can she understeer? can we understeer? can you understeer? can they understeer?
V-ing form
can I be understeering? can you be understeering? can she be understeering? can we be understeering? can you be understeering? can they be understeering?
Perfect
can I have understeered? can you have understeered? can she have understeered? can we have understeered? can you have understeered? can they have understeered?
V-ing perfect
can I have been understeering? can you have been understeering? can she have been understeering? can we have been understeering? can you have been understeering? can they have been understeering?
Interro-negative form
Simple form
can I not understeer? can you not understeer? can she not understeer? can we not understeer? can you not understeer? can they not understeer?
V-ing form
can I not be understeering? can you not be understeering? can she not be understeering? can we not be understeering? can you not be understeering? can they not be understeering?
Perfect
can I not have understeered? can you not have understeered? can she not have understeered? can we not have understeered? can you not have understeered? can they not have understeered?
V-ing perfect
can I not have been understeering? can you not have been understeering? can she not have been understeering? can we not have been understeering? can you not have been understeering? can they not have been understeering?