The document discusses different English modal verbs and their meanings: - CAN, COULD, BE ABLE TO are used to express ability in different tenses. CAN also expresses permission and informal requests. - MUST and HAVE TO express obligation, with MUST used for present tense and HAVE TO for other tenses. - MUSTN'T and CAN'T express prohibition. - SHOULD expresses advice. HAD BETTER also gives advice and is equivalent to 'should'. The document provides examples for each modal verb use. It also lists some online exercises for practicing modal verbs.