could collaborate
Verbo regular: collaborate - collaborated- collaborated

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could collaborate
you could collaborate
he could collaborate
we could collaborate
you could collaborate
they could collaborate 	I could be collaborating
you could be collaborating
he could be collaborating
we could be collaborating
you could be collaborating
they could be collaborating	I could have collaborated
you could have collaborated
he could have collaborated
we could have collaborated
you could have collaborated
they could have collaborated	I could have been collaborating
you could have been collaborating
he could have been collaborating
we could have been collaborating
you could have been collaborating
they could have been collaborating	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I could not collaborate
you could not collaborate
he could not collaborate
we could not collaborate
you could not collaborate
they could not collaborate 	I could not be collaborating
you could not be collaborating
he could not be collaborating
we could not be collaborating
you could not be collaborating
they could not be collaborating	I could not have collaborated
you could not have collaborated
he could not have collaborated
we could not have collaborated
you could not have collaborated
they could not have collaborated	I could not have been collaborating
you could not have been collaborating
he could not have been collaborating
we could not have been collaborating
you could not have been collaborating
they could not have been collaborating	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I collaborate?
could you collaborate?
could he collaborate?
could we collaborate?
could you collaborate?
could they collaborate? 	could I be collaborating?
could you be collaborating?
could he be collaborating?
could we be collaborating?
could you be collaborating?
could they be collaborating? 	could I have collaborated?
could you have collaborated?
could he have collaborated?
could we have collaborated?
could you have collaborated?
could they have collaborated? 	could I have been collaborating?
could you have been collaborating?
could he have been collaborating?
could we have been collaborating?
could you have been collaborating?
could they have been collaborating? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
could I not collaborate?
could you not collaborate?
could he not collaborate?
could we not collaborate?
could you not collaborate?
could they not collaborate? 	could I not be collaborating?
could you not be collaborating?
could he not be collaborating?
could we not be collaborating?
could you not be collaborating?
could they not be collaborating? 	could I not have collaborated?
could you not have collaborated?
could he not have collaborated?
could we not have collaborated?
could you not have collaborated?
could they not have collaborated? 	could I not have been collaborating?
could you not have been collaborating?
could he not have been collaborating?
could we not have been collaborating?
could you not have been collaborating?
could they not have been collaborating?