I should lack you should lack she should lack we should lack you should lack they should lack
V-ing form
I should be lacking you should be lacking she should be lacking we should be lacking you should be lacking they should be lacking
Perfect
I should have lacked you should have lacked she should have lacked we should have lacked you should have lacked they should have lacked
V-ing perfect
I should have been lacking you should have been lacking she should have been lacking we should have been lacking you should have been lacking they should have been lacking
Negation
Simple form
I should not lack you should not lack she should not lack we should not lack you should not lack they should not lack
V-ing form
I should not be lacking you should not be lacking she should not be lacking we should not be lacking you should not be lacking they should not be lacking
Perfect
I should not have lacked you should not have lacked she should not have lacked we should not have lacked you should not have lacked they should not have lacked
V-ing perfect
I should not have been lacking you should not have been lacking she should not have been lacking we should not have been lacking you should not have been lacking they should not have been lacking
Interrogative form
Simple form
should I lack? should you lack? should she lack? should we lack? should you lack? should they lack?
V-ing form
should I be lacking? should you be lacking? should she be lacking? should we be lacking? should you be lacking? should they be lacking?
Perfect
should I have lacked? should you have lacked? should she have lacked? should we have lacked? should you have lacked? should they have lacked?
V-ing perfect
should I have been lacking? should you have been lacking? should she have been lacking? should we have been lacking? should you have been lacking? should they have been lacking?
Interro-negative form
Simple form
should I not lack? should you not lack? should she not lack? should we not lack? should you not lack? should they not lack?
V-ing form
should I not be lacking? should you not be lacking? should she not be lacking? should we not be lacking? should you not be lacking? should they not be lacking?
Perfect
should I not have lacked? should you not have lacked? should she not have lacked? should we not have lacked? should you not have lacked? should they not have lacked?
V-ing perfect
should I not have been lacking? should you not have been lacking? should she not have been lacking? should we not have been lacking? should you not have been lacking? should they not have been lacking?