I could waste you could waste he could waste we could waste you could waste they could waste
V-ing form
I could be wasting you could be wasting he could be wasting we could be wasting you could be wasting they could be wasting
Perfect
I could have wasted you could have wasted he 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 he could have been wasting we could have been wasting you could have been wasting they could have been wasting
Negation
Simple form
I could not waste you could not waste he could not waste we could not waste you could not waste they could not waste
V-ing form
I could not be wasting you could not be wasting he could not be wasting we could not be wasting you could not be wasting they could not be wasting
Perfect
I could not have wasted you could not have wasted he could not have wasted we could not have wasted you could not have wasted they could not have wasted
V-ing perfect
I could not have been wasting you could not have been wasting he could not have been wasting we could not have been wasting you could not have been wasting they could not have been wasting
Interrogative form
Simple form
could I waste? could you waste? could he waste? could we waste? could you waste? could they waste?
V-ing form
could I be wasting? could you be wasting? could he be wasting? could we be wasting? could you be wasting? could they be wasting?
Perfect
could I have wasted? could you have wasted? could he 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 he have been wasting? could we have been wasting? could you have been wasting? could they have been wasting?
Interro-negative form
Simple form
could I not waste? could you not waste? could he not waste? could we not waste? could you not waste? could they not waste?
V-ing form
could I not be wasting? could you not be wasting? could he not be wasting? could we not be wasting? could you not be wasting? could they not be wasting?
Perfect
could I not have wasted? could you not have wasted? could he not have wasted? could we not have wasted? could you not have wasted? could they not have wasted?
V-ing perfect
could I not have been wasting? could you not have been wasting? could he not have been wasting? could we not have been wasting? could you not have been wasting? could they not have been wasting?