Question

How do use 'had' and 'should'?

Answer 1

had is used with past perfect tense like Rina had already eaten the food...
should is used with the moral responsibilities like We should cut our nails weakly..............
if its helpful then mark it as brainliest........

Answer 2

should  is to tell somebody what they ought to do, to give advice like:We should really go and visit them soon. 

had is used for something that was done in the past and still applies. like:The well had been producing clean water.

hope it helps!