Modal verbs

• He might join us for dinner if he finishes his work
  

• Obligation

• Possibility

• Necessity

• Ability

• 
  You must wear a helmet while riding your bike.

• Possibility

• Necessity

• Obligation

• Ability

• If you work hard, you can achieve your goals.

• Necessity

• Ability

• Permission

• Possibility

• They may visit us during their summer vacation.

• Permission

• Ability

• Possibility

• Past Ability

• If it rains, the outdoor event might be rescheduled.

• Possibility

• Ability

• Permission

• Request

• Could you pass me the salt, please?

• Request

• Permission

• Possibility

Could I attend the conference even though I missed the registration deadline?

• Request

• Permission

• Obligation

• Ability

• Possibility