3Barber, Charles. The English Language: A Historical Introduction[M]. Cambridge: Cambridge University Press,1993.
4Blake,N. F. A History of the English Language[ M]. London: Macmillan Press LTD, 1996.
5Comrie, Bernard. Language Universals and Linguistic Typology[ M]. Second edition. Chicago: The Chicago University Press, 1985.
6Hopper, Paul J. , and Elizabeth Closs Traugott. Grammaticalization. Cambridge [ M ]. Cambridge University Press, 1993.
7Langacker, Ronald W. Concept, Image, and Symbol : The Cognitive Basis of Grammar [ M ]. Berlin and New York: Mouton de Gruyter, 1991.
8Langacker, Ronald W. Grammar and Conceptualization [M]. Berlin & New York: Mouton de Gruyter,1999.
9Li, Charles N. and Sandra A. Thompson. Subject and Topic: A New Typology of Language[A]. In Li, (ed.). Subject and Topic [ C ]. Austin: University of Texas Press, 1976. 457 - 90.
10Li, Charles N. and Sandra A. Thompson. Mandarin Chinese: A Functional Reference Grammar[ M ]. Berkeley : University of California Press, 1981.
