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