This video lesson explains the usage of 'has to have', 'have to have', and 'had to have' to express possession ('pass hona chahiye' / 'pass hona chahiye tha'), comparing them with 'should have'. It also covers the usage of modal verbs like 'should', 'must', and 'ought to' for expressing obligations, as well as the modern usage of 'shall' in interrogative sentences.