I could mad you could mad he could mad we could mad you could mad they could mad
V-ing form
I could be mading you could be mading he could be mading we could be mading you could be mading they could be mading
Perfect
I could have maded you could have maded he could have maded we could have maded you could have maded they could have maded
V-ing perfect
I could have been mading you could have been mading he could have been mading we could have been mading you could have been mading they could have been mading
Negation
Simple form
I couldn't mad you couldn't mad he couldn't mad we couldn't mad you couldn't mad they couldn't mad
V-ing form
I couldn't be mading you couldn't be mading he couldn't be mading we couldn't be mading you couldn't be mading they couldn't be mading
Perfect
I couldn't have maded you couldn't have maded he couldn't have maded we couldn't have maded you couldn't have maded they couldn't have maded
V-ing perfect
I couldn't have been mading you couldn't have been mading he couldn't have been mading we couldn't have been mading you couldn't have been mading they couldn't have been mading
Interrogative form
Simple form
could I mad? could you mad? could he mad? could we mad? could you mad? could they mad?
V-ing form
could I be mading? could you be mading? could he be mading? could we be mading? could you be mading? could they be mading?
Perfect
could I have maded? could you have maded? could he have maded? could we have maded? could you have maded? could they have maded?
V-ing perfect
could I have been mading? could you have been mading? could he have been mading? could we have been mading? could you have been mading? could they have been mading?
Interro-negative form
Simple form
couldn't I mad? couldn't you mad? couldn't he mad? couldn't we mad? couldn't you mad? couldn't they mad?
V-ing form
couldn't I be mading? couldn't you be mading? couldn't he be mading? couldn't we be mading? couldn't you be mading? couldn't they be mading?
Perfect
couldn't I have maded? couldn't you have maded? couldn't he have maded? couldn't we have maded? couldn't you have maded? couldn't they have maded?
V-ing perfect
couldn't I have been mading? couldn't you have been mading? couldn't he have been mading? couldn't we have been mading? couldn't you have been mading? couldn't they have been mading?