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