could nitrate
Regular verb: nitrate - nitrated- nitrated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could nitrate
you could nitrate
he could nitrate
we could nitrate
you could nitrate
they could nitrate 	I could be nitrating
you could be nitrating
he could be nitrating
we could be nitrating
you could be nitrating
they could be nitrating	I could have nitrated
you could have nitrated
he could have nitrated
we could have nitrated
you could have nitrated
they could have nitrated	I could have been nitrating
you could have been nitrating
he could have been nitrating
we could have been nitrating
you could have been nitrating
they could have been nitrating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't nitrate
you couldn't nitrate
he couldn't nitrate
we couldn't nitrate
you couldn't nitrate
they couldn't nitrate 	I couldn't be nitrating
you couldn't be nitrating
he couldn't be nitrating
we couldn't be nitrating
you couldn't be nitrating
they couldn't be nitrating	I couldn't have nitrated
you couldn't have nitrated
he couldn't have nitrated
we couldn't have nitrated
you couldn't have nitrated
they couldn't have nitrated	I couldn't have been nitrating
you couldn't have been nitrating
he couldn't have been nitrating
we couldn't have been nitrating
you couldn't have been nitrating
they couldn't have been nitrating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I nitrate?
could you nitrate?
could he nitrate?
could we nitrate?
could you nitrate?
could they nitrate? 	could I be nitrating?
could you be nitrating?
could he be nitrating?
could we be nitrating?
could you be nitrating?
could they be nitrating? 	could I have nitrated?
could you have nitrated?
could he have nitrated?
could we have nitrated?
could you have nitrated?
could they have nitrated? 	could I have been nitrating?
could you have been nitrating?
could he have been nitrating?
could we have been nitrating?
could you have been nitrating?
could they have been nitrating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I nitrate?
couldn't you nitrate?
couldn't he nitrate?
couldn't we nitrate?
couldn't you nitrate?
couldn't they nitrate? 	couldn't I be nitrating?
couldn't you be nitrating?
couldn't he be nitrating?
couldn't we be nitrating?
couldn't you be nitrating?
couldn't they be nitrating? 	couldn't I have nitrated?
couldn't you have nitrated?
couldn't he have nitrated?
couldn't we have nitrated?
couldn't you have nitrated?
couldn't they have nitrated? 	couldn't I have been nitrating?
couldn't you have been nitrating?
couldn't he have been nitrating?
couldn't we have been nitrating?
couldn't you have been nitrating?
couldn't they have been nitrating?