should back
Verbo regular: back - backed- backed

Afirmación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I'd back
you'd back
he'd back
we'd back
you'd back
they'd back 	I'd be backing
you'd be backing
he'd be backing
we'd be backing
you'd be backing
they'd be backing	I should've backed
you should've backed
he should've backed
we should've backed
you should've backed
they should've backed	I should've been backing
you should've been backing
he should've been backing
we should've been backing
you should've been backing
they should've been backing	

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
I shouldn't back
you shouldn't back
he shouldn't back
we shouldn't back
you shouldn't back
they shouldn't back 	I shouldn't be backing
you shouldn't be backing
he shouldn't be backing
we shouldn't be backing
you shouldn't be backing
they shouldn't be backing	I shouldn't have backed
you shouldn't have backed
he shouldn't have backed
we shouldn't have backed
you shouldn't have backed
they shouldn't have backed	I shouldn't have been backing
you shouldn't have been backing
he shouldn't have been backing
we shouldn't have been backing
you shouldn't have been backing
they shouldn't have been backing	

Forma interrogativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
should I back?
should you back?
should he back?
should we back?
should you back?
should they back? 	should I be backing?
should you be backing?
should he be backing?
should we be backing?
should you be backing?
should they be backing? 	should I have backed?
should you have backed?
should he have backed?
should we have backed?
should you have backed?
should they have backed? 	should I have been backing?
should you have been backing?
should he have been backing?
should we have been backing?
should you have been backing?
should they have been backing? 	

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
shouldn't I back?
shouldn't you back?
shouldn't he back?
shouldn't we back?
shouldn't you back?
shouldn't they back? 	shouldn't I be backing?
shouldn't you be backing?
shouldn't he be backing?
shouldn't we be backing?
shouldn't you be backing?
shouldn't they be backing? 	shouldn't I have backed?
shouldn't you have backed?
shouldn't he have backed?
shouldn't we have backed?
shouldn't you have backed?
shouldn't they have backed? 	shouldn't I have been backing?
shouldn't you have been backing?
shouldn't he have been backing?
shouldn't we have been backing?
shouldn't you have been backing?
shouldn't they have been backing?