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