Every language has its own rules of grammar which must be followed by native speakers as well as non-native learners. These rules have differing degrees of play or looseness/strictness, such that some rules are observed without fail by those who are speaking/writing the language correctly, and some rules are episodically or regularly bent by users.
Usage (L usus) is not tantamount to strict observance of grammatical rules. There are always more or less idiomatic ways of using any given language, and the tolerance between idiomaticity and stiltedness is largely a matter of linguistic style. Speakers typically have individual styles that reflect the tolerance that is built into usage. When this tolerance is exceeded––which is largely a matter of judgment––a given usage may become evaluated as a verbal tic.
An interesting case of ticacity is the abuse of the vocative, by which is meant the excessive insertion of the interlocutor’s name in the utterance that is being addressed to him/her. An example of this abuse can regularly be heard from the NPR social science correspondent Shankar Vedantam (as it was today on “Morning Edition”). Mr. Vedantum, who is evidently of South Asian extraction judging by his accent (but whose English is otherwise impeccable), habitually and ticastically inserts the name of the show’s host in his responses to their questions. Different listeners may respond differently to this usage, but Y-H-B considers it an abuse of the vocative.