could yack
Verbo regolare: yack - yacked- yacked

Affermazione 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
I could yack
you could yack
he could yack
we could yack
you could yack
they could yack 	I could be yacking
you could be yacking
he could be yacking
we could be yacking
you could be yacking
they could be yacking	I could have yacked
you could have yacked
he could have yacked
we could have yacked
you could have yacked
they could have yacked	I could have been yacking
you could have been yacking
he could have been yacking
we could have been yacking
you could have been yacking
they could have been yacking	

Negazione 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
I could not yack
you could not yack
he could not yack
we could not yack
you could not yack
they could not yack 	I could not be yacking
you could not be yacking
he could not be yacking
we could not be yacking
you could not be yacking
they could not be yacking	I could not have yacked
you could not have yacked
he could not have yacked
we could not have yacked
you could not have yacked
they could not have yacked	I could not have been yacking
you could not have been yacking
he could not have been yacking
we could not have been yacking
you could not have been yacking
they could not have been yacking	

Forma interrogativa 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
could I yack?
could you yack?
could he yack?
could we yack?
could you yack?
could they yack? 	could I be yacking?
could you be yacking?
could he be yacking?
could we be yacking?
could you be yacking?
could they be yacking? 	could I have yacked?
could you have yacked?
could he have yacked?
could we have yacked?
could you have yacked?
could they have yacked? 	could I have been yacking?
could you have been yacking?
could he have been yacking?
could we have been yacking?
could you have been yacking?
could they have been yacking? 	

Forma interro-negativa 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
could I not yack?
could you not yack?
could he not yack?
could we not yack?
could you not yack?
could they not yack? 	could I not be yacking?
could you not be yacking?
could he not be yacking?
could we not be yacking?
could you not be yacking?
could they not be yacking? 	could I not have yacked?
could you not have yacked?
could he not have yacked?
could we not have yacked?
could you not have yacked?
could they not have yacked? 	could I not have been yacking?
could you not have been yacking?
could he not have been yacking?
could we not have been yacking?
could you not have been yacking?
could they not have been yacking?