Usage of "should" in speaking

 The modal verb "should" is used in speaking to convey several different ideas:

Advice or Recommendation: "Should" is commonly used to give advice or make recommendations.

   - "You should see a doctor if you're feeling unwell."

   - "I think you should apologize to her for what you said."

Expectation or Probability: "Should" can indicate what is expected or likely to happen.

   - "The train should arrive at 3:00 PM, but there could be delays."

   - "He should know the answer; he's been studying all week."

Obligation or Duty: "Should" can express a sense of obligation or duty, although it is not as strong as "must."

   - "I should finish this report before the deadline."

   - "We should help those in need whenever we can."

Conditional Statements: "Should" is often used in conditional statements to express what is expected to happen under certain conditions.

   - "If you study hard, you should pass the exam."

   - "Should it rain, we'll need to postpone the outdoor event."

Surprise or Disbelief: In some cases, "should" can express surprise or disbelief at an unexpected event.

   - "He's not here yet? He should have arrived by now."

   - "The car won't start? It should be working perfectly fine."

Polite Suggestions or Offers: "Should" can be used to make polite suggestions or offers.

   - "You should come over for dinner sometime."

   - "Should I help you with that?"

Overall, "should" is a versatile modal verb used in spoken English to offer advice, express expectations, indicate obligations, frame conditional statements, show surprise, and make polite suggestions or offers. Its usage depends on the context and the speaker's intention.