English verb conjugation
SHOULD QUACK

Regular verb: quack - quacked - quacked

Affirmation

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