could bum
Verbo regular: bum - bummed- bummed

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could bum
you could bum
he could bum
we could bum
you could bum
they could bum 	I could be bumming
you could be bumming
he could be bumming
we could be bumming
you could be bumming
they could be bumming	I could have bummed
you could have bummed
he could have bummed
we could have bummed
you could have bummed
they could have bummed	I could have been bumming
you could have been bumming
he could have been bumming
we could have been bumming
you could have been bumming
they could have been bumming	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I couldn't bum
you couldn't bum
he couldn't bum
we couldn't bum
you couldn't bum
they couldn't bum 	I couldn't be bumming
you couldn't be bumming
he couldn't be bumming
we couldn't be bumming
you couldn't be bumming
they couldn't be bumming	I couldn't have bummed
you couldn't have bummed
he couldn't have bummed
we couldn't have bummed
you couldn't have bummed
they couldn't have bummed	I couldn't have been bumming
you couldn't have been bumming
he couldn't have been bumming
we couldn't have been bumming
you couldn't have been bumming
they couldn't have been bumming	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I bum?
could you bum?
could he bum?
could we bum?
could you bum?
could they bum? 	could I be bumming?
could you be bumming?
could he be bumming?
could we be bumming?
could you be bumming?
could they be bumming? 	could I have bummed?
could you have bummed?
could he have bummed?
could we have bummed?
could you have bummed?
could they have bummed? 	could I have been bumming?
could you have been bumming?
could he have been bumming?
could we have been bumming?
could you have been bumming?
could they have been bumming? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
couldn't I bum?
couldn't you bum?
couldn't he bum?
couldn't we bum?
couldn't you bum?
couldn't they bum? 	couldn't I be bumming?
couldn't you be bumming?
couldn't he be bumming?
couldn't we be bumming?
couldn't you be bumming?
couldn't they be bumming? 	couldn't I have bummed?
couldn't you have bummed?
couldn't he have bummed?
couldn't we have bummed?
couldn't you have bummed?
couldn't they have bummed? 	couldn't I have been bumming?
couldn't you have been bumming?
couldn't he have been bumming?
couldn't we have been bumming?
couldn't you have been bumming?
couldn't they have been bumming?