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