could cross-fertilize
Regular verb: cross-fertilize - cross-fertilized- cross-fertilized

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could cross-fertilize
you could cross-fertilize
he could cross-fertilize
we could cross-fertilize
you could cross-fertilize
they could cross-fertilize 	I could be cross-fertilizing
you could be cross-fertilizing
he could be cross-fertilizing
we could be cross-fertilizing
you could be cross-fertilizing
they could be cross-fertilizing	I could have cross-fertilized
you could have cross-fertilized
he could have cross-fertilized
we could have cross-fertilized
you could have cross-fertilized
they could have cross-fertilized	I could have been cross-fertilizing
you could have been cross-fertilizing
he could have been cross-fertilizing
we could have been cross-fertilizing
you could have been cross-fertilizing
they could have been cross-fertilizing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't cross-fertilize
you couldn't cross-fertilize
he couldn't cross-fertilize
we couldn't cross-fertilize
you couldn't cross-fertilize
they couldn't cross-fertilize 	I couldn't be cross-fertilizing
you couldn't be cross-fertilizing
he couldn't be cross-fertilizing
we couldn't be cross-fertilizing
you couldn't be cross-fertilizing
they couldn't be cross-fertilizing	I couldn't have cross-fertilized
you couldn't have cross-fertilized
he couldn't have cross-fertilized
we couldn't have cross-fertilized
you couldn't have cross-fertilized
they couldn't have cross-fertilized	I couldn't have been cross-fertilizing
you couldn't have been cross-fertilizing
he couldn't have been cross-fertilizing
we couldn't have been cross-fertilizing
you couldn't have been cross-fertilizing
they couldn't have been cross-fertilizing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I cross-fertilize?
could you cross-fertilize?
could he cross-fertilize?
could we cross-fertilize?
could you cross-fertilize?
could they cross-fertilize? 	could I be cross-fertilizing?
could you be cross-fertilizing?
could he be cross-fertilizing?
could we be cross-fertilizing?
could you be cross-fertilizing?
could they be cross-fertilizing? 	could I have cross-fertilized?
could you have cross-fertilized?
could he have cross-fertilized?
could we have cross-fertilized?
could you have cross-fertilized?
could they have cross-fertilized? 	could I have been cross-fertilizing?
could you have been cross-fertilizing?
could he have been cross-fertilizing?
could we have been cross-fertilizing?
could you have been cross-fertilizing?
could they have been cross-fertilizing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I cross-fertilize?
couldn't you cross-fertilize?
couldn't he cross-fertilize?
couldn't we cross-fertilize?
couldn't you cross-fertilize?
couldn't they cross-fertilize? 	couldn't I be cross-fertilizing?
couldn't you be cross-fertilizing?
couldn't he be cross-fertilizing?
couldn't we be cross-fertilizing?
couldn't you be cross-fertilizing?
couldn't they be cross-fertilizing? 	couldn't I have cross-fertilized?
couldn't you have cross-fertilized?
couldn't he have cross-fertilized?
couldn't we have cross-fertilized?
couldn't you have cross-fertilized?
couldn't they have cross-fertilized? 	couldn't I have been cross-fertilizing?
couldn't you have been cross-fertilizing?
couldn't he have been cross-fertilizing?
couldn't we have been cross-fertilizing?
couldn't you have been cross-fertilizing?
couldn't they have been cross-fertilizing?