could fog
Regular verb: fog - fogged- fogged

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could fog
you could fog
he could fog
we could fog
you could fog
they could fog 	I could be fogging
you could be fogging
he could be fogging
we could be fogging
you could be fogging
they could be fogging	I could have fogged
you could have fogged
he could have fogged
we could have fogged
you could have fogged
they could have fogged	I could have been fogging
you could have been fogging
he could have been fogging
we could have been fogging
you could have been fogging
they could have been fogging	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not fog
you could not fog
he could not fog
we could not fog
you could not fog
they could not fog 	I could not be fogging
you could not be fogging
he could not be fogging
we could not be fogging
you could not be fogging
they could not be fogging	I could not have fogged
you could not have fogged
he could not have fogged
we could not have fogged
you could not have fogged
they could not have fogged	I could not have been fogging
you could not have been fogging
he could not have been fogging
we could not have been fogging
you could not have been fogging
they could not have been fogging	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I fog?
could you fog?
could he fog?
could we fog?
could you fog?
could they fog? 	could I be fogging?
could you be fogging?
could he be fogging?
could we be fogging?
could you be fogging?
could they be fogging? 	could I have fogged?
could you have fogged?
could he have fogged?
could we have fogged?
could you have fogged?
could they have fogged? 	could I have been fogging?
could you have been fogging?
could he have been fogging?
could we have been fogging?
could you have been fogging?
could they have been fogging? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not fog?
could you not fog?
could he not fog?
could we not fog?
could you not fog?
could they not fog? 	could I not be fogging?
could you not be fogging?
could he not be fogging?
could we not be fogging?
could you not be fogging?
could they not be fogging? 	could I not have fogged?
could you not have fogged?
could he not have fogged?
could we not have fogged?
could you not have fogged?
could they not have fogged? 	could I not have been fogging?
could you not have been fogging?
could he not have been fogging?
could we not have been fogging?
could you not have been fogging?
could they not have been fogging?