should quack
Regular verb: quack - quacked- quacked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I should quack
you should quack
she should quack
we should quack
you should quack
they should quack 	I should be quacking
you should be quacking
she should be quacking
we should be quacking
you should be quacking
they should be quacking	I should have quacked
you should have quacked
she should have quacked
we should have quacked
you should have quacked
they should have quacked	I should have been quacking
you should have been quacking
she should have been quacking
we should have been quacking
you should have been quacking
they should have been quacking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I should not quack
you should not quack
she should not quack
we should not quack
you should not quack
they should not quack 	I should not be quacking
you should not be quacking
she should not be quacking
we should not be quacking
you should not be quacking
they should not be quacking	I should not have quacked
you should not have quacked
she should not have quacked
we should not have quacked
you should not have quacked
they should not have quacked	I should not have been quacking
you should not have been quacking
she should not have been quacking
we should not have been quacking
you should not have been quacking
they should not have been quacking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I quack?
should you quack?
should she quack?
should we quack?
should you quack?
should they quack? 	should I be quacking?
should you be quacking?
should she be quacking?
should we be quacking?
should you be quacking?
should they be quacking? 	should I have quacked?
should you have quacked?
should she 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 she 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 	
should I not quack?
should you not quack?
should she not quack?
should we not quack?
should you not quack?
should they not quack? 	should I not be quacking?
should you not be quacking?
should she not be quacking?
should we not be quacking?
should you not be quacking?
should they not be quacking? 	should I not have quacked?
should you not have quacked?
should she not have quacked?
should we not have quacked?
should you not have quacked?
should they not have quacked? 	should I not have been quacking?
should you not have been quacking?
should she not have been quacking?
should we not have been quacking?
should you not have been quacking?
should they not have been quacking?