could lucubrate
Regular verb: lucubrate - lucubrated- lucubrated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could lucubrate
you could lucubrate
he could lucubrate
we could lucubrate
you could lucubrate
they could lucubrate 	I could be lucubrating
you could be lucubrating
he could be lucubrating
we could be lucubrating
you could be lucubrating
they could be lucubrating	I could have lucubrated
you could have lucubrated
he could have lucubrated
we could have lucubrated
you could have lucubrated
they could have lucubrated	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 	
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I could not lucubrate
you could not lucubrate
he could not lucubrate
we could not lucubrate
you could not lucubrate
they could not lucubrate 	I could not be lucubrating
you could not be lucubrating
he could not be lucubrating
we could not be lucubrating
you could not be lucubrating
they could not be lucubrating	I could not have lucubrated
you could not have lucubrated
he could not have lucubrated
we could not have lucubrated
you could not have lucubrated
they could not have lucubrated	I could not have been lucubrating
you could not have been lucubrating
he could not have been lucubrating
we could not have been lucubrating
you could not have been lucubrating
they could not have been lucubrating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I lucubrate?
could you lucubrate?
could he lucubrate?
could we lucubrate?
could you lucubrate?
could they lucubrate? 	could I be lucubrating?
could you be lucubrating?
could he be lucubrating?
could we be lucubrating?
could you be lucubrating?
could they be lucubrating? 	could I have lucubrated?
could you have lucubrated?
could he have lucubrated?
could we have lucubrated?
could you have lucubrated?
could they have lucubrated? 	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 	V-ing form 	Perfect 	V-ing perfect 	
could I not lucubrate?
could you not lucubrate?
could he not lucubrate?
could we not lucubrate?
could you not lucubrate?
could they not lucubrate? 	could I not be lucubrating?
could you not be lucubrating?
could he not be lucubrating?
could we not be lucubrating?
could you not be lucubrating?
could they not be lucubrating? 	could I not have lucubrated?
could you not have lucubrated?
could he not have lucubrated?
could we not have lucubrated?
could you not have lucubrated?
could they not have lucubrated? 	could I not have been lucubrating?
could you not have been lucubrating?
could he not have been lucubrating?
could we not have been lucubrating?
could you not have been lucubrating?
could they not have been lucubrating?