should quack
Regular verb: quack - quacked- quacked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I'd quack
you'd quack
he'd quack
we'd quack
you'd quack
they'd quack 	I'd be quacking
you'd be quacking
he'd be quacking
we'd be quacking
you'd be quacking
they'd be quacking	I should've quacked
you should've quacked
he should've quacked
we should've quacked
you should've quacked
they should've quacked	I should've been quacking
you should've been quacking
he should've been quacking
we should've been quacking
you should've been quacking
they should've been quacking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I shouldn't quack
you shouldn't quack
he shouldn't quack
we shouldn't quack
you shouldn't quack
they shouldn't quack 	I shouldn't be quacking
you shouldn't be quacking
he shouldn't be quacking
we shouldn't be quacking
you shouldn't be quacking
they shouldn't be quacking	I shouldn't have quacked
you shouldn't have quacked
he shouldn't have quacked
we shouldn't have quacked
you shouldn't have quacked
they shouldn't have quacked	I shouldn't have been quacking
you shouldn't have been quacking
he shouldn't have been quacking
we shouldn't have been quacking
you shouldn't have been quacking
they shouldn't have been quacking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I quack?
should you quack?
should he quack?
should we quack?
should you quack?
should they quack? 	should I be quacking?
should you be quacking?
should he be quacking?
should we be quacking?
should you be quacking?
should they be quacking? 	should I have quacked?
should you have quacked?
should he have quacked?
should we have quacked?
should you have quacked?
should they have quacked? 	should I have been quacking?
should you have been quacking?
should he have been quacking?
should we have been quacking?
should you have been quacking?
should they have been quacking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
shouldn't I quack?
shouldn't you quack?
shouldn't he quack?
shouldn't we quack?
shouldn't you quack?
shouldn't they quack? 	shouldn't I be quacking?
shouldn't you be quacking?
shouldn't he be quacking?
shouldn't we be quacking?
shouldn't you be quacking?
shouldn't they be quacking? 	shouldn't I have quacked?
shouldn't you have quacked?
shouldn't he have quacked?
shouldn't we have quacked?
shouldn't you have quacked?
shouldn't they have quacked? 	shouldn't I have been quacking?
shouldn't you have been quacking?
shouldn't he have been quacking?
shouldn't we have been quacking?
shouldn't you have been quacking?
shouldn't they have been quacking?