should sum
Regular verb: sum - summed- summed

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I'd sum
you'd sum
he'd sum
we'd sum
you'd sum
they'd sum 	I'd be summing
you'd be summing
he'd be summing
we'd be summing
you'd be summing
they'd be summing	I should've summed
you should've summed
he should've summed
we should've summed
you should've summed
they should've summed	I should've been summing
you should've been summing
he should've been summing
we should've been summing
you should've been summing
they should've been summing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I shouldn't sum
you shouldn't sum
he shouldn't sum
we shouldn't sum
you shouldn't sum
they shouldn't sum 	I shouldn't be summing
you shouldn't be summing
he shouldn't be summing
we shouldn't be summing
you shouldn't be summing
they shouldn't be summing	I shouldn't have summed
you shouldn't have summed
he shouldn't have summed
we shouldn't have summed
you shouldn't have summed
they shouldn't have summed	I shouldn't have been summing
you shouldn't have been summing
he shouldn't have been summing
we shouldn't have been summing
you shouldn't have been summing
they shouldn't have been summing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I sum?
should you sum?
should he sum?
should we sum?
should you sum?
should they sum? 	should I be summing?
should you be summing?
should he be summing?
should we be summing?
should you be summing?
should they be summing? 	should I have summed?
should you have summed?
should he have summed?
should we have summed?
should you have summed?
should they have summed? 	should I have been summing?
should you have been summing?
should he have been summing?
should we have been summing?
should you have been summing?
should they have been summing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
shouldn't I sum?
shouldn't you sum?
shouldn't he sum?
shouldn't we sum?
shouldn't you sum?
shouldn't they sum? 	shouldn't I be summing?
shouldn't you be summing?
shouldn't he be summing?
shouldn't we be summing?
shouldn't you be summing?
shouldn't they be summing? 	shouldn't I have summed?
shouldn't you have summed?
shouldn't he have summed?
shouldn't we have summed?
shouldn't you have summed?
shouldn't they have summed? 	shouldn't I have been summing?
shouldn't you have been summing?
shouldn't he have been summing?
shouldn't we have been summing?
shouldn't you have been summing?
shouldn't they have been summing?