should

(modal, auxiliary verb, defective) Used before a verb to indicate the simple future tense in the first person singular or plural.

“I hope that we shall win the game.”

Used similarly to indicate determination or obligation in the second and third persons singular or plural.

“(determination): You shall go to the ball!”

Used in questions with the first person singular or plural to suggest a possible future action.

“Let us examine that, shall we?”

To owe.

A statement of what ought to be the case as opposed to what is the case.

To make a statement of what ought to be true, as opposed to reality.

(auxiliary) Be obliged to; have an obligation to; indicates that the subject of the sentence has some obligation to execute the sentence predicate or that the speaker has some strong advice but has no authority to enforce it.

“What do I think? What should I do?”

(auxiliary) ought to; speaker's opinion, or advice that an action is correct, beneficial, or desirable.

“I should exercise more often, but I'm too lazy.”

(auxiliary) Will be likely to (become or do something); indicates a degree of possibility or probability that the subject of the sentence is likely to execute the sentence predicate.

“When you press this button, the pilot flame should ignite.”

(auxiliary, subjunctive) Used as a variant of the present subjunctive.

“If I should be late, go without me.”

(auxiliary) A variant of would when used with first person subjects.

“I should be lucky if I were you.”