could concertina
Verbo regular: concertina - concertinaed- concertinaed

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could concertina
you could concertina
he could concertina
we could concertina
you could concertina
they could concertina 	I could be concertinaing
you could be concertinaing
he could be concertinaing
we could be concertinaing
you could be concertinaing
they could be concertinaing	I could have concertinaed
you could have concertinaed
he could have concertinaed
we could have concertinaed
you could have concertinaed
they could have concertinaed	I could have been concertinaing
you could have been concertinaing
he could have been concertinaing
we could have been concertinaing
you could have been concertinaing
they could have been concertinaing	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could not concertina
you could not concertina
he could not concertina
we could not concertina
you could not concertina
they could not concertina 	I could not be concertinaing
you could not be concertinaing
he could not be concertinaing
we could not be concertinaing
you could not be concertinaing
they could not be concertinaing	I could not have concertinaed
you could not have concertinaed
he could not have concertinaed
we could not have concertinaed
you could not have concertinaed
they could not have concertinaed	I could not have been concertinaing
you could not have been concertinaing
he could not have been concertinaing
we could not have been concertinaing
you could not have been concertinaing
they could not have been concertinaing	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I concertina?
could you concertina?
could he concertina?
could we concertina?
could you concertina?
could they concertina? 	could I be concertinaing?
could you be concertinaing?
could he be concertinaing?
could we be concertinaing?
could you be concertinaing?
could they be concertinaing? 	could I have concertinaed?
could you have concertinaed?
could he have concertinaed?
could we have concertinaed?
could you have concertinaed?
could they have concertinaed? 	could I have been concertinaing?
could you have been concertinaing?
could he have been concertinaing?
could we have been concertinaing?
could you have been concertinaing?
could they have been concertinaing? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I not concertina?
could you not concertina?
could he not concertina?
could we not concertina?
could you not concertina?
could they not concertina? 	could I not be concertinaing?
could you not be concertinaing?
could he not be concertinaing?
could we not be concertinaing?
could you not be concertinaing?
could they not be concertinaing? 	could I not have concertinaed?
could you not have concertinaed?
could he not have concertinaed?
could we not have concertinaed?
could you not have concertinaed?
could they not have concertinaed? 	could I not have been concertinaing?
could you not have been concertinaing?
could he not have been concertinaing?
could we not have been concertinaing?
could you not have been concertinaing?
could they not have been concertinaing?