should contribute
Verbo regular: contribute - contributed- contributed

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I'd contribute
you'd contribute
she'd contribute
we'd contribute
you'd contribute
they'd contribute 	I'd be contributing
you'd be contributing
she'd be contributing
we'd be contributing
you'd be contributing
they'd be contributing	I should've contributed
you should've contributed
she should've contributed
we should've contributed
you should've contributed
they should've contributed	I should've been contributing
you should've been contributing
she should've been contributing
we should've been contributing
you should've been contributing
they should've been contributing	

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

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

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