could overfertilize
Regular verb: overfertilize - overfertilized- overfertilized

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could overfertilize
you could overfertilize
he could overfertilize
we could overfertilize
you could overfertilize
they could overfertilize 	I could be overfertilizing
you could be overfertilizing
he could be overfertilizing
we could be overfertilizing
you could be overfertilizing
they could be overfertilizing	I could have overfertilized
you could have overfertilized
he could have overfertilized
we could have overfertilized
you could have overfertilized
they could have overfertilized	I could have been overfertilizing
you could have been overfertilizing
he could have been overfertilizing
we could have been overfertilizing
you could have been overfertilizing
they could have been overfertilizing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't overfertilize
you couldn't overfertilize
he couldn't overfertilize
we couldn't overfertilize
you couldn't overfertilize
they couldn't overfertilize 	I couldn't be overfertilizing
you couldn't be overfertilizing
he couldn't be overfertilizing
we couldn't be overfertilizing
you couldn't be overfertilizing
they couldn't be overfertilizing	I couldn't have overfertilized
you couldn't have overfertilized
he couldn't have overfertilized
we couldn't have overfertilized
you couldn't have overfertilized
they couldn't have overfertilized	I couldn't have been overfertilizing
you couldn't have been overfertilizing
he couldn't have been overfertilizing
we couldn't have been overfertilizing
you couldn't have been overfertilizing
they couldn't have been overfertilizing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I overfertilize?
could you overfertilize?
could he overfertilize?
could we overfertilize?
could you overfertilize?
could they overfertilize? 	could I be overfertilizing?
could you be overfertilizing?
could he be overfertilizing?
could we be overfertilizing?
could you be overfertilizing?
could they be overfertilizing? 	could I have overfertilized?
could you have overfertilized?
could he have overfertilized?
could we have overfertilized?
could you have overfertilized?
could they have overfertilized? 	could I have been overfertilizing?
could you have been overfertilizing?
could he have been overfertilizing?
could we have been overfertilizing?
could you have been overfertilizing?
could they have been overfertilizing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I overfertilize?
couldn't you overfertilize?
couldn't he overfertilize?
couldn't we overfertilize?
couldn't you overfertilize?
couldn't they overfertilize? 	couldn't I be overfertilizing?
couldn't you be overfertilizing?
couldn't he be overfertilizing?
couldn't we be overfertilizing?
couldn't you be overfertilizing?
couldn't they be overfertilizing? 	couldn't I have overfertilized?
couldn't you have overfertilized?
couldn't he have overfertilized?
couldn't we have overfertilized?
couldn't you have overfertilized?
couldn't they have overfertilized? 	couldn't I have been overfertilizing?
couldn't you have been overfertilizing?
couldn't he have been overfertilizing?
couldn't we have been overfertilizing?
couldn't you have been overfertilizing?
couldn't they have been overfertilizing?