MODAL

modal [verb], modal auxiliary [noun] [C] [specialized] - a verb used with another verb to express an idea such as possibility that is not expressed by the main verb of a sentenceThe modal verbs in English are 'can', 'could', 'may', 'might', 'must', 'ought', 'shall', 'should', 'will' and 'would'.The first verb in the following sentence is a modal: We must pay the gas bill.