My rather long-winded definition of fluency is the ability to speak quickly and effectively on a subject while demonstrating an easy flow of language in which thought is articulated effortlessly with meaning being fully conveyed on a broad range of topics.
Problems with fluency include:
— long pauses
— badly mangled syntax
— badly distorted pronunciation
(the cause 80% of communication breakdowns at my, admittedly rough, estimate)
— poor prosody
However, for a better understanding of the nature of the aptitude it is helpful to turn to the thesaurus to further consider some words that come under the semantic field of fluency:
The words highlighted in red indicate an emphasis on form rather than meaning. When speaking a language, fluency is more important than accuracy, That is to say, meaning is ultimately more important than form. And thus fluency is slightly different to proficiency. Language is, first and foremost, about communicating. That means getting a message across, and cosmetic grammar and pronunciation inaccuracies do not, for the most part, preclude that.
Native speakers may have narrow vocabularies, limited discourse topics & strategies, inaccurate word use, use non-standard grammar, and may even be illiterate. But they are still able to communicate well enough to be fully understood in any situation or subject they wish or need to talk about. A person like this is fluent, but not proficient.
Of course teachers do not want to create illiterate, inaccurate
speakers but it is important to know what communicative priorities are.
Accurate language use, both in speaking and writing, can be acquired
relatively easily once fluency has been established. Fluency on the
other hand, takes a lot more work even after a person has learned
English for years, has a good knowledge of grammatical rules, and has
acquired a large vocabulary.