could invoice
Verbo regular: invoice - invoiced- invoiced

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could invoice
you could invoice
she could invoice
we could invoice
you could invoice
they could invoice 	I could be invoicing
you could be invoicing
she could be invoicing
we could be invoicing
you could be invoicing
they could be invoicing	I could have invoiced
you could have invoiced
she could have invoiced
we could have invoiced
you could have invoiced
they could have invoiced	I could have been invoicing
you could have been invoicing
she could have been invoicing
we could have been invoicing
you could have been invoicing
they could have been invoicing	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I could not invoice
you could not invoice
she could not invoice
we could not invoice
you could not invoice
they could not invoice 	I could not be invoicing
you could not be invoicing
she could not be invoicing
we could not be invoicing
you could not be invoicing
they could not be invoicing	I could not have invoiced
you could not have invoiced
she could not have invoiced
we could not have invoiced
you could not have invoiced
they could not have invoiced	I could not have been invoicing
you could not have been invoicing
she could not have been invoicing
we could not have been invoicing
you could not have been invoicing
they could not have been invoicing	

Forma interrogativa 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I invoice?
could you invoice?
could she invoice?
could we invoice?
could you invoice?
could they invoice? 	could I be invoicing?
could you be invoicing?
could she be invoicing?
could we be invoicing?
could you be invoicing?
could they be invoicing? 	could I have invoiced?
could you have invoiced?
could she have invoiced?
could we have invoiced?
could you have invoiced?
could they have invoiced? 	could I have been invoicing?
could you have been invoicing?
could she have been invoicing?
could we have been invoicing?
could you have been invoicing?
could they have been invoicing? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
could I not invoice?
could you not invoice?
could she not invoice?
could we not invoice?
could you not invoice?
could they not invoice? 	could I not be invoicing?
could you not be invoicing?
could she not be invoicing?
could we not be invoicing?
could you not be invoicing?
could they not be invoicing? 	could I not have invoiced?
could you not have invoiced?
could she not have invoiced?
could we not have invoiced?
could you not have invoiced?
could they not have invoiced? 	could I not have been invoicing?
could you not have been invoicing?
could she not have been invoicing?
could we not have been invoicing?
could you not have been invoicing?
could they not have been invoicing?