A discourse marker is a word or phrase that plays a role in managing the flow and structure of discourse. Since their main function is at the level of discourse (sequences of utterances) rather than at the level of utterances or sentences, discourse markers are relatively syntax-independent and usually do not change the truth conditional meaning of the sentence. Examples of discourse markers include the particles "oh", "well", "now", "then", "you know", and "I mean", and the 'discourse connectives', "so", "because", "and", "but", and "or".
== Definition ==
In Practical English Usage, Michael Swan...