Imperfective aspect is an aspect that expresses an event or state, with respect to its internal structure, instead of expressing it as a simple whole.
Habitual aspect with
Pei, Mario A., and Frank Gaynor. 1954.A dictionary of linguistics. New York: Philosophical Library.
Mish, Frederick (editor). 1991.Webster's ninth new collegiate dictionary. Springfield, MA: Merriam-Webster. 1,564 pages. 0877795088; indexed 0877795096; deluxe 087779510X.
Ducrot, Oswald, and Tzvetan Todorov. 1979.Encyclopedic dictionary of the science of language. Baltimore, MD: John Hopkins University.
Crystal, David. 1985.A dictionary of linguistics and phonetics. 2nd edition. New York: Basil Blackwell.
Comrie, Bernard. 1976a.Aspect: An introduction to verbal aspect and related problems. Cambridge, England: Cambridge University.