could flash
Regular verb: flash - flashed- flashed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could flash
you could flash
he could flash
we could flash
you could flash
they could flash 	I could be flashing
you could be flashing
he could be flashing
we could be flashing
you could be flashing
they could be flashing	I could have flashed
you could have flashed
he could have flashed
we could have flashed
you could have flashed
they could have flashed	I could have been flashing
you could have been flashing
he could have been flashing
we could have been flashing
you could have been flashing
they could have been flashing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't flash
you couldn't flash
he couldn't flash
we couldn't flash
you couldn't flash
they couldn't flash 	I couldn't be flashing
you couldn't be flashing
he couldn't be flashing
we couldn't be flashing
you couldn't be flashing
they couldn't be flashing	I couldn't have flashed
you couldn't have flashed
he couldn't have flashed
we couldn't have flashed
you couldn't have flashed
they couldn't have flashed	I couldn't have been flashing
you couldn't have been flashing
he couldn't have been flashing
we couldn't have been flashing
you couldn't have been flashing
they couldn't have been flashing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I flash?
could you flash?
could he flash?
could we flash?
could you flash?
could they flash? 	could I be flashing?
could you be flashing?
could he be flashing?
could we be flashing?
could you be flashing?
could they be flashing? 	could I have flashed?
could you have flashed?
could he have flashed?
could we have flashed?
could you have flashed?
could they have flashed? 	could I have been flashing?
could you have been flashing?
could he have been flashing?
could we have been flashing?
could you have been flashing?
could they have been flashing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I flash?
couldn't you flash?
couldn't he flash?
couldn't we flash?
couldn't you flash?
couldn't they flash? 	couldn't I be flashing?
couldn't you be flashing?
couldn't he be flashing?
couldn't we be flashing?
couldn't you be flashing?
couldn't they be flashing? 	couldn't I have flashed?
couldn't you have flashed?
couldn't he have flashed?
couldn't we have flashed?
couldn't you have flashed?
couldn't they have flashed? 	couldn't I have been flashing?
couldn't you have been flashing?
couldn't he have been flashing?
couldn't we have been flashing?
couldn't you have been flashing?
couldn't they have been flashing?