Items about modal verbs:

1. Modal verb for obligation: must, have to, should, ought to
2. Modal verb for possibility: may, might, could, can
3. Modal verb for necessity: need to, have to, must, should
4. Modal verb for ability: can, could, be able to, may
5. Modal verb for chance: might, could, may, can

Sentences using the words obligation, possibility, necessity, ability, and chance:

1. Obligation: I must finish my homework before going out with my friends.
2. Possibility: It may rain tomorrow, so we should bring umbrellas.
3. Necessity: You need to eat a balanced diet to maintain good health.
4. Ability: She can speak five different languages fluently.
5. Chance: If you study hard, you might pass the exam with flying colors.

Sentences using the words possibly, ably, necessarily, requisitely, and responsibly:

1. Possibly: I will possibly attend the party if I finish my work on time.
2. Ably: The team was ably led by their captain to victory.
3. Necessarily: To become a doctor, it is necessarily required to complete medical school.
4. Requisitely: The job position requisitely demands excellent communication skills.
5. Responsibly: He always handles his tasks responsibly and never misses a deadline.