auxiliary verb

1. shall I had hoped I should see you
2. used to express obligation, duty, propriety, or desirability you should ask first, the plants should be watered weekly
3. used to express expectation or probability he should be here soon, I should know by tomorrow
4. used to express a future condition if I should die tomorrow, if you should be late
5. used in polite or tentative expression of opinion I should think they will be pleased

Etymology: ME scholde < OE sceolde, pt. of sceal, scal, I am obliged: see shall