SHOULD
(a) synonymous in ordinary English speech with would (a), (b) and (c);
(b) expressing advisability, recommendation, obligation: more or less synonymous with ought (a);
(c) should have, expressing reproach or regret at omission: more or less synonymous with ought (c);
(d) expressing probability: more or less synonymous with ought (d);
(e) expressing modest assertion: various formulae, e.g.
I should think that . . . Mнe кaжeтся, что . . .
I should say that . . . Я бы скaзaл(a), что . . .
(a) synonymous in ordinary English speech with would (a), (b) and (c);
(b) expressing advisability, recommendation, obligation: more or less synonymous with ought (a);
(c) should have, expressing reproach or regret at omission: more or less synonymous with ought (c);
(d) expressing probability: more or less synonymous with ought (d);
(e) expressing modest assertion: various formulae, e.g.
I should think that . . . Mнe кaжeтся, что . . .
I should say that . . . Я бы скaзaл(a), что . . .