I could lug you could lug he could lug we could lug you could lug they could lug
V-ing form
I could be lugging you could be lugging he could be lugging we could be lugging you could be lugging they could be lugging
Perfect
I could have lugged you could have lugged he could have lugged we could have lugged you could have lugged they could have lugged
V-ing perfect
I could have been lugging you could have been lugging he could have been lugging we could have been lugging you could have been lugging they could have been lugging
Negation
Simple form
I could not lug you could not lug he could not lug we could not lug you could not lug they could not lug
V-ing form
I could not be lugging you could not be lugging he could not be lugging we could not be lugging you could not be lugging they could not be lugging
Perfect
I could not have lugged you could not have lugged he could not have lugged we could not have lugged you could not have lugged they could not have lugged
V-ing perfect
I could not have been lugging you could not have been lugging he could not have been lugging we could not have been lugging you could not have been lugging they could not have been lugging
Interrogative form
Simple form
could I lug? could you lug? could he lug? could we lug? could you lug? could they lug?
V-ing form
could I be lugging? could you be lugging? could he be lugging? could we be lugging? could you be lugging? could they be lugging?
Perfect
could I have lugged? could you have lugged? could he have lugged? could we have lugged? could you have lugged? could they have lugged?
V-ing perfect
could I have been lugging? could you have been lugging? could he have been lugging? could we have been lugging? could you have been lugging? could they have been lugging?
Interro-negative form
Simple form
could I not lug? could you not lug? could he not lug? could we not lug? could you not lug? could they not lug?
V-ing form
could I not be lugging? could you not be lugging? could he not be lugging? could we not be lugging? could you not be lugging? could they not be lugging?
Perfect
could I not have lugged? could you not have lugged? could he not have lugged? could we not have lugged? could you not have lugged? could they not have lugged?
V-ing perfect
could I not have been lugging? could you not have been lugging? could he not have been lugging? could we not have been lugging? could you not have been lugging? could they not have been lugging?