I could wither you could wither she could wither we could wither you could wither they could wither
V-ing form
I could be withering you could be withering she could be withering we could be withering you could be withering they could be withering
Perfect
I could have withered you could have withered she could have withered we could have withered you could have withered they could have withered
V-ing perfect
I could have been withering you could have been withering she could have been withering we could have been withering you could have been withering they could have been withering
Negation
Simple form
I couldn't wither you couldn't wither she couldn't wither we couldn't wither you couldn't wither they couldn't wither
V-ing form
I couldn't be withering you couldn't be withering she couldn't be withering we couldn't be withering you couldn't be withering they couldn't be withering
Perfect
I couldn't have withered you couldn't have withered she couldn't have withered we couldn't have withered you couldn't have withered they couldn't have withered
V-ing perfect
I couldn't have been withering you couldn't have been withering she couldn't have been withering we couldn't have been withering you couldn't have been withering they couldn't have been withering
Interrogative form
Simple form
could I wither? could you wither? could she wither? could we wither? could you wither? could they wither?
V-ing form
could I be withering? could you be withering? could she be withering? could we be withering? could you be withering? could they be withering?
Perfect
could I have withered? could you have withered? could she have withered? could we have withered? could you have withered? could they have withered?
V-ing perfect
could I have been withering? could you have been withering? could she have been withering? could we have been withering? could you have been withering? could they have been withering?
Interro-negative form
Simple form
couldn't I wither? couldn't you wither? couldn't she wither? couldn't we wither? couldn't you wither? couldn't they wither?
V-ing form
couldn't I be withering? couldn't you be withering? couldn't she be withering? couldn't we be withering? couldn't you be withering? couldn't they be withering?
Perfect
couldn't I have withered? couldn't you have withered? couldn't she have withered? couldn't we have withered? couldn't you have withered? couldn't they have withered?
V-ing perfect
couldn't I have been withering? couldn't you have been withering? couldn't she have been withering? couldn't we have been withering? couldn't you have been withering? couldn't they have been withering?