(As in conditional sentences)
"If I had time, I should go to the gym."
"If I had had time, I should have gone to the gym."
I am not sure about American English, but I reckon in British English if the subject is I" or "We" then "should" can be used in the sense of "would", as in "I would go to the gym" and, "I would have gone to the gym". Am I correct? (Because in British English "I will go to the gym" = "I shall go to the gym")