English Modals: Must, Have To, Might, Could

Study Notes

Must:
- Indicates a strong obligation or necessity.
- Often used for personal obligations or when the speaker feels strongly.
- Example: You must finish your homework.
Have to:
- Indicates an obligation but often comes from an external source or authority.
- Example: I have to attend the meeting at 10 AM.

Might:
- Used to suggest a possibility or to make a suggestion.
- Less assertive than "must" or "should".
- Example: You might want to try a different approach.
Could:
- Indicates a suggestion or possibility, often implies capability or potential.
- Example: You could consider changing your study habits.

Should:
- Used to give advice or make recommendations.
- Implies a mild obligation or expectation.
- Example: You should check your work for errors.
Ought to:
- Similar to "should," often used interchangeably.
- Slightly stronger in implying moral obligation.
- Example: You ought to help your neighbors.

Obligation:
- Implies a duty or requirement to act.
- Often conveyed by "must," "have to," "should," and "ought to."
- Example: You must wear a seatbelt.
Suggestion:
- Offers advice or recommendations without imposing a duty.
- Conveyed by "might," "could," and "should" in a less assertive manner.
- Example: You might want to join a study group.

Must not (mustn't):
- Indicates a strong prohibition or something that is not allowed.
- Typically conveys a personal or moral stance.
- Example: You must not lie to your friends.
Cannot (can't):
- Indicates an absolute prohibition, often due to rules, laws, or physical limitations.
- Example: You cannot park here; it’s against the law.

Must signifies a strong obligation or necessity, often relating to personal duties.
Example of must: "You must finish your homework" conveys urgency.
Have to suggests obligation from external sources, such as rules or requirements.
Example of have to: "I have to attend the meeting at 10 AM" implies an obligation imposed by circumstances.

Might expresses a possibility or offers a suggestion, presenting a less forceful tone than "must" or "should."
Example usage of might: "You might want to try a different approach" proposes an option without pressure.
Could suggests capability or potential, often used for making recommendations.
Example usage of could: "You could consider changing your study habits" implies feasible alternatives.

Should provides advice or recommendations, indicating a mild obligation or expectation.
Example of should: "You should check your work for errors" suggests a good practice.
Ought to is similar to "should" but carries a slightly stronger moral implication.
Example of ought to: "You ought to help your neighbors" emphasizes ethical responsibility.

Obligation denotes a requirement to act and is expressed through terms like "must," "have to," "should," and "ought to."
Example of obligation: "You must wear a seatbelt" underscores a legal or safety requirement.
Suggestion offers advice or recommendations without enforcing a duty, conveyed using "might," "could," and sometimes "should" in a softer context.
Example of suggestion: "You might want to join a study group" presents a non-essential option.

Must not (mustn't) conveys a strong prohibition, often reflecting personal or moral beliefs.
Example of must not: "You must not lie to your friends" highlights ethical conduct.
Cannot (can't) indicates absolute prohibitions based on rules, laws, or limitations.
Example of cannot: "You cannot park here; it’s against the law" points out a legal restriction.