could stifle
Verbo regular: stifle - stifled- stifled

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could stifle
you could stifle
he could stifle
we could stifle
you could stifle
they could stifle 	I could be stifling
you could be stifling
he could be stifling
we could be stifling
you could be stifling
they could be stifling	I could have stifled
you could have stifled
he could have stifled
we could have stifled
you could have stifled
they could have stifled	I could have been stifling
you could have been stifling
he could have been stifling
we could have been stifling
you could have been stifling
they could have been stifling	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could not stifle
you could not stifle
he could not stifle
we could not stifle
you could not stifle
they could not stifle 	I could not be stifling
you could not be stifling
he could not be stifling
we could not be stifling
you could not be stifling
they could not be stifling	I could not have stifled
you could not have stifled
he could not have stifled
we could not have stifled
you could not have stifled
they could not have stifled	I could not have been stifling
you could not have been stifling
he could not have been stifling
we could not have been stifling
you could not have been stifling
they could not have been stifling	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I stifle?
could you stifle?
could he stifle?
could we stifle?
could you stifle?
could they stifle? 	could I be stifling?
could you be stifling?
could he be stifling?
could we be stifling?
could you be stifling?
could they be stifling? 	could I have stifled?
could you have stifled?
could he have stifled?
could we have stifled?
could you have stifled?
could they have stifled? 	could I have been stifling?
could you have been stifling?
could he have been stifling?
could we have been stifling?
could you have been stifling?
could they have been stifling? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I not stifle?
could you not stifle?
could he not stifle?
could we not stifle?
could you not stifle?
could they not stifle? 	could I not be stifling?
could you not be stifling?
could he not be stifling?
could we not be stifling?
could you not be stifling?
could they not be stifling? 	could I not have stifled?
could you not have stifled?
could he not have stifled?
could we not have stifled?
could you not have stifled?
could they not have stifled? 	could I not have been stifling?
could you not have been stifling?
could he not have been stifling?
could we not have been stifling?
could you not have been stifling?
could they not have been stifling?