could tail
Verbo regular: tail - tailed- tailed

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could tail
you could tail
she could tail
we could tail
you could tail
they could tail 	I could be tailing
you could be tailing
she could be tailing
we could be tailing
you could be tailing
they could be tailing	I could have tailed
you could have tailed
she could have tailed
we could have tailed
you could have tailed
they could have tailed	I could have been tailing
you could have been tailing
she could have been tailing
we could have been tailing
you could have been tailing
they could have been tailing	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could not tail
you could not tail
she could not tail
we could not tail
you could not tail
they could not tail 	I could not be tailing
you could not be tailing
she could not be tailing
we could not be tailing
you could not be tailing
they could not be tailing	I could not have tailed
you could not have tailed
she could not have tailed
we could not have tailed
you could not have tailed
they could not have tailed	I could not have been tailing
you could not have been tailing
she could not have been tailing
we could not have been tailing
you could not have been tailing
they could not have been tailing	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I tail?
could you tail?
could she tail?
could we tail?
could you tail?
could they tail? 	could I be tailing?
could you be tailing?
could she be tailing?
could we be tailing?
could you be tailing?
could they be tailing? 	could I have tailed?
could you have tailed?
could she have tailed?
could we have tailed?
could you have tailed?
could they have tailed? 	could I have been tailing?
could you have been tailing?
could she have been tailing?
could we have been tailing?
could you have been tailing?
could they have been tailing? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I not tail?
could you not tail?
could she not tail?
could we not tail?
could you not tail?
could they not tail? 	could I not be tailing?
could you not be tailing?
could she not be tailing?
could we not be tailing?
could you not be tailing?
could they not be tailing? 	could I not have tailed?
could you not have tailed?
could she not have tailed?
could we not have tailed?
could you not have tailed?
could they not have tailed? 	could I not have been tailing?
could you not have been tailing?
could she not have been tailing?
could we not have been tailing?
could you not have been tailing?
could they not have been tailing?