The notion of "work" has arisen out of man s activities in the world and what typically characterizes this notion is the cognitive stereotypes of "work",which fall into four categories,namely,those involving respectively,subject,attitud.

The traditional linguists\' study lies only in the modal verbs,while the functional linguists focuses their attention on the modality itself in terms of a new perspective and they made a new explanations to one of the basic modality—epidemic modality.