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