Modal verbs like “could” and “would” are often used with past tenses to convey various meanings within hypothetical or conditional statements. When combined with a past participle, they form perfect modal verbs (e.g., could have, would have). Here’s how they function in different contexts:

1. Possibility: When used with past tenses, modal verbs can express the possibility of an action that did not happen in the past. For example, “She could have studied harder for the exam” implies the possibility of better preparation in the past.

2. Politeness: Modal verbs like “would” are commonly used in polite requests or offers in the past. For instance, “Would you please pass the salt?” is a polite way to ask someone to pass the salt.

3. Hypothetical outcomes: In hypothetical statements, modal verbs with past tenses can convey potential outcomes under different circumstances. For example, “If I had known, I would have helped” expresses a hypothetical situation where the speaker would have offered assistance if they had been aware of the need.

4. Regrets or Wishes: Modal verbs can also express regrets or wishes about past actions. For example, “I wish I could have attended the party” conveys the speaker’s regret about missing the party.

Overall, modal verbs like “could” and “would” add nuances to past tenses by indicating possibility, politeness, hypothetical outcomes, regrets, or wishes in a