could develop
Regular verb: develop - developed- developed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could develop
you could develop
he could develop
we could develop
you could develop
they could develop 	I could be developing
you could be developing
he could be developing
we could be developing
you could be developing
they could be developing	I could have developed
you could have developed
he could have developed
we could have developed
you could have developed
they could have developed	I could have been developing
you could have been developing
he could have been developing
we could have been developing
you could have been developing
they could have been developing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not develop
you could not develop
he could not develop
we could not develop
you could not develop
they could not develop 	I could not be developing
you could not be developing
he could not be developing
we could not be developing
you could not be developing
they could not be developing	I could not have developed
you could not have developed
he could not have developed
we could not have developed
you could not have developed
they could not have developed	I could not have been developing
you could not have been developing
he could not have been developing
we could not have been developing
you could not have been developing
they could not have been developing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I develop?
could you develop?
could he develop?
could we develop?
could you develop?
could they develop? 	could I be developing?
could you be developing?
could he be developing?
could we be developing?
could you be developing?
could they be developing? 	could I have developed?
could you have developed?
could he have developed?
could we have developed?
could you have developed?
could they have developed? 	could I have been developing?
could you have been developing?
could he have been developing?
could we have been developing?
could you have been developing?
could they have been developing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not develop?
could you not develop?
could he not develop?
could we not develop?
could you not develop?
could they not develop? 	could I not be developing?
could you not be developing?
could he not be developing?
could we not be developing?
could you not be developing?
could they not be developing? 	could I not have developed?
could you not have developed?
could he not have developed?
could we not have developed?
could you not have developed?
could they not have developed? 	could I not have been developing?
could you not have been developing?
could he not have been developing?
could we not have been developing?
could you not have been developing?
could they not have been developing?