can contribute
Verbo regular: contribute - contributed- contributed

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I can contribute
you can contribute
she can contribute
we can contribute
you can contribute
they can contribute 	I can be contributing
you can be contributing
she can be contributing
we can be contributing
you can be contributing
they can be contributing	I can have contributed
you can have contributed
she can have contributed
we can have contributed
you can have contributed
they can have contributed	I can have been contributing
you can have been contributing
she can have been contributing
we can have been contributing
you can have been contributing
they can have been contributing	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I cannot contribute
you cannot contribute
she cannot contribute
we cannot contribute
you cannot contribute
they cannot contribute 	I cannot be contributing
you cannot be contributing
she cannot be contributing
we cannot be contributing
you cannot be contributing
they cannot be contributing	I cannot have contributed
you cannot have contributed
she cannot have contributed
we cannot have contributed
you cannot have contributed
they cannot have contributed	I cannot have been contributing
you cannot have been contributing
she cannot have been contributing
we cannot have been contributing
you cannot have been contributing
they cannot have been contributing	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
can I contribute?
can you contribute?
can she contribute?
can we contribute?
can you contribute?
can they contribute? 	can I be contributing?
can you be contributing?
can she be contributing?
can we be contributing?
can you be contributing?
can they be contributing? 	can I have contributed?
can you have contributed?
can she have contributed?
can we have contributed?
can you have contributed?
can they have contributed? 	can I have been contributing?
can you have been contributing?
can she have been contributing?
can we have been contributing?
can you have been contributing?
can they have been contributing? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
can I not contribute?
can you not contribute?
can she not contribute?
can we not contribute?
can you not contribute?
can they not contribute? 	can I not be contributing?
can you not be contributing?
can she not be contributing?
can we not be contributing?
can you not be contributing?
can they not be contributing? 	can I not have contributed?
can you not have contributed?
can she not have contributed?
can we not have contributed?
can you not have contributed?
can they not have contributed? 	can I not have been contributing?
can you not have been contributing?
can she not have been contributing?
can we not have been contributing?
can you not have been contributing?
can they not have been contributing?