could surf
Regular verb: surf - surfed- surfed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could surf
you could surf
she could surf
we could surf
you could surf
they could surf 	I could be surfing
you could be surfing
she could be surfing
we could be surfing
you could be surfing
they could be surfing	I could have surfed
you could have surfed
she could have surfed
we could have surfed
you could have surfed
they could have surfed	I could have been surfing
you could have been surfing
she could have been surfing
we could have been surfing
you could have been surfing
they could have been surfing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't surf
you couldn't surf
she couldn't surf
we couldn't surf
you couldn't surf
they couldn't surf 	I couldn't be surfing
you couldn't be surfing
she couldn't be surfing
we couldn't be surfing
you couldn't be surfing
they couldn't be surfing	I couldn't have surfed
you couldn't have surfed
she couldn't have surfed
we couldn't have surfed
you couldn't have surfed
they couldn't have surfed	I couldn't have been surfing
you couldn't have been surfing
she couldn't have been surfing
we couldn't have been surfing
you couldn't have been surfing
they couldn't have been surfing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I surf?
could you surf?
could she surf?
could we surf?
could you surf?
could they surf? 	could I be surfing?
could you be surfing?
could she be surfing?
could we be surfing?
could you be surfing?
could they be surfing? 	could I have surfed?
could you have surfed?
could she have surfed?
could we have surfed?
could you have surfed?
could they have surfed? 	could I have been surfing?
could you have been surfing?
could she have been surfing?
could we have been surfing?
could you have been surfing?
could they have been surfing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I surf?
couldn't you surf?
couldn't she surf?
couldn't we surf?
couldn't you surf?
couldn't they surf? 	couldn't I be surfing?
couldn't you be surfing?
couldn't she be surfing?
couldn't we be surfing?
couldn't you be surfing?
couldn't they be surfing? 	couldn't I have surfed?
couldn't you have surfed?
couldn't she have surfed?
couldn't we have surfed?
couldn't you have surfed?
couldn't they have surfed? 	couldn't I have been surfing?
couldn't you have been surfing?
couldn't she have been surfing?
couldn't we have been surfing?
couldn't you have been surfing?
couldn't they have been surfing?