could tumble
Verbo regular: tumble - tumbled- tumbled

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could tumble
you could tumble
he could tumble
we could tumble
you could tumble
they could tumble 	I could be tumbling
you could be tumbling
he could be tumbling
we could be tumbling
you could be tumbling
they could be tumbling	I could have tumbled
you could have tumbled
he could have tumbled
we could have tumbled
you could have tumbled
they could have tumbled	I could have been tumbling
you could have been tumbling
he could have been tumbling
we could have been tumbling
you could have been tumbling
they could have been tumbling	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could not tumble
you could not tumble
he could not tumble
we could not tumble
you could not tumble
they could not tumble 	I could not be tumbling
you could not be tumbling
he could not be tumbling
we could not be tumbling
you could not be tumbling
they could not be tumbling	I could not have tumbled
you could not have tumbled
he could not have tumbled
we could not have tumbled
you could not have tumbled
they could not have tumbled	I could not have been tumbling
you could not have been tumbling
he could not have been tumbling
we could not have been tumbling
you could not have been tumbling
they could not have been tumbling	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I tumble?
could you tumble?
could he tumble?
could we tumble?
could you tumble?
could they tumble? 	could I be tumbling?
could you be tumbling?
could he be tumbling?
could we be tumbling?
could you be tumbling?
could they be tumbling? 	could I have tumbled?
could you have tumbled?
could he have tumbled?
could we have tumbled?
could you have tumbled?
could they have tumbled? 	could I have been tumbling?
could you have been tumbling?
could he have been tumbling?
could we have been tumbling?
could you have been tumbling?
could they have been tumbling? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I not tumble?
could you not tumble?
could he not tumble?
could we not tumble?
could you not tumble?
could they not tumble? 	could I not be tumbling?
could you not be tumbling?
could he not be tumbling?
could we not be tumbling?
could you not be tumbling?
could they not be tumbling? 	could I not have tumbled?
could you not have tumbled?
could he not have tumbled?
could we not have tumbled?
could you not have tumbled?
could they not have tumbled? 	could I not have been tumbling?
could you not have been tumbling?
could he not have been tumbling?
could we not have been tumbling?
could you not have been tumbling?
could they not have been tumbling?