should yack
Regular verb: yack - yacked- yacked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I'd yack
you'd yack
he'd yack
we'd yack
you'd yack
they'd yack 	I'd be yacking
you'd be yacking
he'd be yacking
we'd be yacking
you'd be yacking
they'd be yacking	I should've yacked
you should've yacked
he should've yacked
we should've yacked
you should've yacked
they should've yacked	I should've been yacking
you should've been yacking
he should've been yacking
we should've been yacking
you should've been yacking
they should've been yacking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I shouldn't yack
you shouldn't yack
he shouldn't yack
we shouldn't yack
you shouldn't yack
they shouldn't yack 	I shouldn't be yacking
you shouldn't be yacking
he shouldn't be yacking
we shouldn't be yacking
you shouldn't be yacking
they shouldn't be yacking	I shouldn't have yacked
you shouldn't have yacked
he shouldn't have yacked
we shouldn't have yacked
you shouldn't have yacked
they shouldn't have yacked	I shouldn't have been yacking
you shouldn't have been yacking
he shouldn't have been yacking
we shouldn't have been yacking
you shouldn't have been yacking
they shouldn't have been yacking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I yack?
should you yack?
should he yack?
should we yack?
should you yack?
should they yack? 	should I be yacking?
should you be yacking?
should he be yacking?
should we be yacking?
should you be yacking?
should they be yacking? 	should I have yacked?
should you have yacked?
should he have yacked?
should we have yacked?
should you have yacked?
should they have yacked? 	should I have been yacking?
should you have been yacking?
should he have been yacking?
should we have been yacking?
should you have been yacking?
should they have been yacking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
shouldn't I yack?
shouldn't you yack?
shouldn't he yack?
shouldn't we yack?
shouldn't you yack?
shouldn't they yack? 	shouldn't I be yacking?
shouldn't you be yacking?
shouldn't he be yacking?
shouldn't we be yacking?
shouldn't you be yacking?
shouldn't they be yacking? 	shouldn't I have yacked?
shouldn't you have yacked?
shouldn't he have yacked?
shouldn't we have yacked?
shouldn't you have yacked?
shouldn't they have yacked? 	shouldn't I have been yacking?
shouldn't you have been yacking?
shouldn't he have been yacking?
shouldn't we have been yacking?
shouldn't you have been yacking?
shouldn't they have been yacking?