could listen
Regular verb: listen - listened- listened

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could listen
you could listen
he could listen
we could listen
you could listen
they could listen 	I could be listening
you could be listening
he could be listening
we could be listening
you could be listening
they could be listening	I could have listened
you could have listened
he could have listened
we could have listened
you could have listened
they could have listened	I could have been listening
you could have been listening
he could have been listening
we could have been listening
you could have been listening
they could have been listening	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not listen
you could not listen
he could not listen
we could not listen
you could not listen
they could not listen 	I could not be listening
you could not be listening
he could not be listening
we could not be listening
you could not be listening
they could not be listening	I could not have listened
you could not have listened
he could not have listened
we could not have listened
you could not have listened
they could not have listened	I could not have been listening
you could not have been listening
he could not have been listening
we could not have been listening
you could not have been listening
they could not have been listening	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I listen?
could you listen?
could he listen?
could we listen?
could you listen?
could they listen? 	could I be listening?
could you be listening?
could he be listening?
could we be listening?
could you be listening?
could they be listening? 	could I have listened?
could you have listened?
could he have listened?
could we have listened?
could you have listened?
could they have listened? 	could I have been listening?
could you have been listening?
could he have been listening?
could we have been listening?
could you have been listening?
could they have been listening? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not listen?
could you not listen?
could he not listen?
could we not listen?
could you not listen?
could they not listen? 	could I not be listening?
could you not be listening?
could he not be listening?
could we not be listening?
could you not be listening?
could they not be listening? 	could I not have listened?
could you not have listened?
could he not have listened?
could we not have listened?
could you not have listened?
could they not have listened? 	could I not have been listening?
could you not have been listening?
could he not have been listening?
could we not have been listening?
could you not have been listening?
could they not have been listening?