The levels of a language are mentioned in the last sentence ...

One of the popular myths about the English language is that somewhere people are still speaking the kind of English that Chaucer or Shakespeare or Milton spoke. This myth does, of course, have some foundation in fact, though the mythical versions repeated above are gross exaggerations. The relevant fact is that some regional dialects of English retain old forms which have disappeared from the standard form of the language. This conservatism in colonial varieties is, rather unfortunately, termed 'colonial lag' - unfortunately because the term gives the impression that the colonial variety will (or should) one day catch up with the home variety, though this is unlikely ever to happen. Colonial lag is a potential factor in distinguishing colonial varieties from their home counterparts in all levels of language: phonology, morphology, syntax, semantics and lexis.

BAUER, L. An Introduction to International Varieties of English. Hong Kong University Press, Hong Kong, 2003. [Adapted].