What's done is done says the confident Lady Macbeth after the play's opening scenes; What done cannot be undone is her remorseful lament at the end. The literal meaning is the same, but the effect is very different. It is in precise analysis of such detail that a real contribution can be made to people's capacity to read and listen critically, and to resist being manipulated by what is said. The analysis of such language and its effects is known as Critical Linguistic, or , when placed in a larger social context and seen as part of a process of social change, as Critical Discourse Analysis.