should contribute
Verbo regular: contribute - contributed- contributed

Afirmação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I'd contribute
you'd contribute
he'd contribute
we'd contribute
you'd contribute
they'd contribute 	I'd be contributing
you'd be contributing
he'd be contributing
we'd be contributing
you'd be contributing
they'd be contributing	I should've contributed
you should've contributed
he 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
he should've been contributing
we should've been contributing
you should've been contributing
they should've been contributing	

Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
I shouldn't contribute
you shouldn't contribute
he 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
he 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
he 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
he 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 com V-ing 	Perfeito 	Perfeito com V-ing 	
should I contribute?
should you contribute?
should he contribute?
should we contribute?
should you contribute?
should they contribute? 	should I be contributing?
should you be contributing?
should he be contributing?
should we be contributing?
should you be contributing?
should they be contributing? 	should I have contributed?
should you have contributed?
should he 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 he have been contributing?
should we have been contributing?
should you have been contributing?
should they have been contributing? 	

Forma interro-Negação 	
Forma simple 	Forma com V-ing 	Perfeito 	Perfeito com V-ing 	
shouldn't I contribute?
shouldn't you contribute?
shouldn't he 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 he 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 he 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 he have been contributing?
shouldn't we have been contributing?
shouldn't you have been contributing?
shouldn't they have been contributing?