Difference between "fluency" and "fluidity"
Fluent seems to most commonly refer to language mastery, but in that context isn't it just saying that its delivery is fluid?
If so, am I communicating something different when using one over another or are they essentially interchangeable?
I will compare the adjectives fluent and fluid.
The etymologies of the words are shared and so is one of the meanings:
smooth and unconstrained in movement
So, when you speak about movement (literary or as metaphor), it is interchangeable.
Otherwise it is not:
fluent
- easy and graceful in shape
- expressing yourself readily, clearly, effectivelyfluid
- characteristic of a fluid; capable of flowing and easily changing shape
- subject to change; variable
- affording change (especially in social status)
- in cash or easily convertible to cash
NOTE: If you read the etymology entry, you will find that fluent was
Used interchangeably with fluid in Elizabethan times.
As a second language teacher, I constantly run into theories about fluidity and fluency. Fluency is a more complicated issue than fluidity. Fluency includes the skill of being able to express specific content (often spontaneously) with ease. Fluidity has more to do with speed of speech, intonation, rhythm. For example, a person who pauses and hesitates a lot would not have achieved fluidity. One can be fluent without being fluid, and one can be fluid without being fluent. Fluidity is more attached to style and delivery, and fluent is more attached to content and ease of communication. Fluidity is often a sub-category of fluency.
With respect to language, I would say that you should be fluent in a language before you can be accused of fluid delivery. Fluent means "Able to express oneself readily and effortlessly" (tFD; italics mine). I am fluent in English, but not everything I say is delivered fluidly. The other meaning @Unreason gave ("easy and graceful in shape") does not apply to language mastery.
No, they are not interchangeable. You can be fluent in a language, but you can't be fluid in it.
I believe fluency refers to your knowledge of the language, i.e, using concise language, whereas fluidity refers to flow of speech. I live in Poland and it is incredibly irritating to listen to otherwise very intelligent people speak because they pause after a few words and utter loudly "ehhhhh" or "mmmmm" then continue with their conversation, repeating these irritating interruptions to the end.