could flail
Regular verb: flail - flailed- flailed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could flail
you could flail
he could flail
we could flail
you could flail
they could flail 	I could be flailing
you could be flailing
he could be flailing
we could be flailing
you could be flailing
they could be flailing	I could have flailed
you could have flailed
he could have flailed
we could have flailed
you could have flailed
they could have flailed	I could have been flailing
you could have been flailing
he could have been flailing
we could have been flailing
you could have been flailing
they could have been flailing	

Negation 	
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I could not flail
you could not flail
he could not flail
we could not flail
you could not flail
they could not flail 	I could not be flailing
you could not be flailing
he could not be flailing
we could not be flailing
you could not be flailing
they could not be flailing	I could not have flailed
you could not have flailed
he could not have flailed
we could not have flailed
you could not have flailed
they could not have flailed	I could not have been flailing
you could not have been flailing
he could not have been flailing
we could not have been flailing
you could not have been flailing
they could not have been flailing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I flail?
could you flail?
could he flail?
could we flail?
could you flail?
could they flail? 	could I be flailing?
could you be flailing?
could he be flailing?
could we be flailing?
could you be flailing?
could they be flailing? 	could I have flailed?
could you have flailed?
could he have flailed?
could we have flailed?
could you have flailed?
could they have flailed? 	could I have been flailing?
could you have been flailing?
could he have been flailing?
could we have been flailing?
could you have been flailing?
could they have been flailing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not flail?
could you not flail?
could he not flail?
could we not flail?
could you not flail?
could they not flail? 	could I not be flailing?
could you not be flailing?
could he not be flailing?
could we not be flailing?
could you not be flailing?
could they not be flailing? 	could I not have flailed?
could you not have flailed?
could he not have flailed?
could we not have flailed?
could you not have flailed?
could they not have flailed? 	could I not have been flailing?
could you not have been flailing?
could he not have been flailing?
could we not have been flailing?
could you not have been flailing?
could they not have been flailing?