I should challenge you should challenge he should challenge we should challenge you should challenge they should challenge
V-ing form
I should be challenging you should be challenging he should be challenging we should be challenging you should be challenging they should be challenging
Perfect
I should have challenged you should have challenged he should have challenged we should have challenged you should have challenged they should have challenged
V-ing perfect
I should have been challenging you should have been challenging he should have been challenging we should have been challenging you should have been challenging they should have been challenging
Negation
Simple form
I should not challenge you should not challenge he should not challenge we should not challenge you should not challenge they should not challenge
V-ing form
I should not be challenging you should not be challenging he should not be challenging we should not be challenging you should not be challenging they should not be challenging
Perfect
I should not have challenged you should not have challenged he should not have challenged we should not have challenged you should not have challenged they should not have challenged
V-ing perfect
I should not have been challenging you should not have been challenging he should not have been challenging we should not have been challenging you should not have been challenging they should not have been challenging
Interrogative form
Simple form
should I challenge? should you challenge? should he challenge? should we challenge? should you challenge? should they challenge?
V-ing form
should I be challenging? should you be challenging? should he be challenging? should we be challenging? should you be challenging? should they be challenging?
Perfect
should I have challenged? should you have challenged? should he have challenged? should we have challenged? should you have challenged? should they have challenged?
V-ing perfect
should I have been challenging? should you have been challenging? should he have been challenging? should we have been challenging? should you have been challenging? should they have been challenging?
Interro-negative form
Simple form
should I not challenge? should you not challenge? should he not challenge? should we not challenge? should you not challenge? should they not challenge?
V-ing form
should I not be challenging? should you not be challenging? should he not be challenging? should we not be challenging? should you not be challenging? should they not be challenging?
Perfect
should I not have challenged? should you not have challenged? should he not have challenged? should we not have challenged? should you not have challenged? should they not have challenged?
V-ing perfect
should I not have been challenging? should you not have been challenging? should he not have been challenging? should we not have been challenging? should you not have been challenging? should they not have been challenging?