could cavern
Verbo regular: cavern - caverned- caverned

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could cavern
you could cavern
he could cavern
we could cavern
you could cavern
they could cavern 	I could be caverning
you could be caverning
he could be caverning
we could be caverning
you could be caverning
they could be caverning	I could have caverned
you could have caverned
he could have caverned
we could have caverned
you could have caverned
they could have caverned	I could have been caverning
you could have been caverning
he could have been caverning
we could have been caverning
you could have been caverning
they could have been caverning	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could not cavern
you could not cavern
he could not cavern
we could not cavern
you could not cavern
they could not cavern 	I could not be caverning
you could not be caverning
he could not be caverning
we could not be caverning
you could not be caverning
they could not be caverning	I could not have caverned
you could not have caverned
he could not have caverned
we could not have caverned
you could not have caverned
they could not have caverned	I could not have been caverning
you could not have been caverning
he could not have been caverning
we could not have been caverning
you could not have been caverning
they could not have been caverning	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I cavern?
could you cavern?
could he cavern?
could we cavern?
could you cavern?
could they cavern? 	could I be caverning?
could you be caverning?
could he be caverning?
could we be caverning?
could you be caverning?
could they be caverning? 	could I have caverned?
could you have caverned?
could he have caverned?
could we have caverned?
could you have caverned?
could they have caverned? 	could I have been caverning?
could you have been caverning?
could he have been caverning?
could we have been caverning?
could you have been caverning?
could they have been caverning? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I not cavern?
could you not cavern?
could he not cavern?
could we not cavern?
could you not cavern?
could they not cavern? 	could I not be caverning?
could you not be caverning?
could he not be caverning?
could we not be caverning?
could you not be caverning?
could they not be caverning? 	could I not have caverned?
could you not have caverned?
could he not have caverned?
could we not have caverned?
could you not have caverned?
could they not have caverned? 	could I not have been caverning?
could you not have been caverning?
could he not have been caverning?
could we not have been caverning?
could you not have been caverning?
could they not have been caverning?