I should thumbtack you should thumbtack he should thumbtack we should thumbtack you should thumbtack they should thumbtack
V-ing form
I should be thumbtacking you should be thumbtacking he should be thumbtacking we should be thumbtacking you should be thumbtacking they should be thumbtacking
Perfect
I should have thumbtacked you should have thumbtacked he should have thumbtacked we should have thumbtacked you should have thumbtacked they should have thumbtacked
V-ing perfect
I should have been thumbtacking you should have been thumbtacking he should have been thumbtacking we should have been thumbtacking you should have been thumbtacking they should have been thumbtacking
Negation
Simple form
I should not thumbtack you should not thumbtack he should not thumbtack we should not thumbtack you should not thumbtack they should not thumbtack
V-ing form
I should not be thumbtacking you should not be thumbtacking he should not be thumbtacking we should not be thumbtacking you should not be thumbtacking they should not be thumbtacking
Perfect
I should not have thumbtacked you should not have thumbtacked he should not have thumbtacked we should not have thumbtacked you should not have thumbtacked they should not have thumbtacked
V-ing perfect
I should not have been thumbtacking you should not have been thumbtacking he should not have been thumbtacking we should not have been thumbtacking you should not have been thumbtacking they should not have been thumbtacking
Interrogative form
Simple form
should I thumbtack? should you thumbtack? should he thumbtack? should we thumbtack? should you thumbtack? should they thumbtack?
V-ing form
should I be thumbtacking? should you be thumbtacking? should he be thumbtacking? should we be thumbtacking? should you be thumbtacking? should they be thumbtacking?
Perfect
should I have thumbtacked? should you have thumbtacked? should he have thumbtacked? should we have thumbtacked? should you have thumbtacked? should they have thumbtacked?
V-ing perfect
should I have been thumbtacking? should you have been thumbtacking? should he have been thumbtacking? should we have been thumbtacking? should you have been thumbtacking? should they have been thumbtacking?
Interro-negative form
Simple form
should I not thumbtack? should you not thumbtack? should he not thumbtack? should we not thumbtack? should you not thumbtack? should they not thumbtack?
V-ing form
should I not be thumbtacking? should you not be thumbtacking? should he not be thumbtacking? should we not be thumbtacking? should you not be thumbtacking? should they not be thumbtacking?
Perfect
should I not have thumbtacked? should you not have thumbtacked? should he not have thumbtacked? should we not have thumbtacked? should you not have thumbtacked? should they not have thumbtacked?
V-ing perfect
should I not have been thumbtacking? should you not have been thumbtacking? should he not have been thumbtacking? should we not have been thumbtacking? should you not have been thumbtacking? should they not have been thumbtacking?