A demonstrative is a determiner that is used deictically to indicate a referent's spatial, temporal, or discourse location.
A demonstrative functions as:
(English)
Quirk, Randolph, S. Greenbaum, G. Leech, and J. Svartvik. 1985.A comprehensive grammar of the English language. London: Longman.
Mish, Frederick (editor). 1991.Webster's ninth new collegiate dictionary. Springfield, MA: Merriam-Webster. 1,564 pages. 0877795088; indexed 0877795096; deluxe 087779510X.
Hartmann, R.R.K., and F.C. Stork. 1972.Dictionary of language and linguistics. London: Applied Science.