could glass
Verbo regular: glass - glassed- glassed

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could glass
you could glass
he could glass
we could glass
you could glass
they could glass 	I could be glassing
you could be glassing
he could be glassing
we could be glassing
you could be glassing
they could be glassing	I could have glassed
you could have glassed
he could have glassed
we could have glassed
you could have glassed
they could have glassed	I could have been glassing
you could have been glassing
he could have been glassing
we could have been glassing
you could have been glassing
they could have been glassing	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I couldn't glass
you couldn't glass
he couldn't glass
we couldn't glass
you couldn't glass
they couldn't glass 	I couldn't be glassing
you couldn't be glassing
he couldn't be glassing
we couldn't be glassing
you couldn't be glassing
they couldn't be glassing	I couldn't have glassed
you couldn't have glassed
he couldn't have glassed
we couldn't have glassed
you couldn't have glassed
they couldn't have glassed	I couldn't have been glassing
you couldn't have been glassing
he couldn't have been glassing
we couldn't have been glassing
you couldn't have been glassing
they couldn't have been glassing	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I glass?
could you glass?
could he glass?
could we glass?
could you glass?
could they glass? 	could I be glassing?
could you be glassing?
could he be glassing?
could we be glassing?
could you be glassing?
could they be glassing? 	could I have glassed?
could you have glassed?
could he have glassed?
could we have glassed?
could you have glassed?
could they have glassed? 	could I have been glassing?
could you have been glassing?
could he have been glassing?
could we have been glassing?
could you have been glassing?
could they have been glassing? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
couldn't I glass?
couldn't you glass?
couldn't he glass?
couldn't we glass?
couldn't you glass?
couldn't they glass? 	couldn't I be glassing?
couldn't you be glassing?
couldn't he be glassing?
couldn't we be glassing?
couldn't you be glassing?
couldn't they be glassing? 	couldn't I have glassed?
couldn't you have glassed?
couldn't he have glassed?
couldn't we have glassed?
couldn't you have glassed?
couldn't they have glassed? 	couldn't I have been glassing?
couldn't you have been glassing?
couldn't he have been glassing?
couldn't we have been glassing?
couldn't you have been glassing?
couldn't they have been glassing?