What Does It Mean to Be Fluent in a Language?

I’ve been learning Spanish since I was eight years old–I can read, write, and speak it very well, but I have never once said that I am “fluent”. I don’t even know what that really means!

The word fluency comes from the Latin word fluentem, which means “to flow”. The dictionary definition of fluency states that it means “being able to speak and write quickly or easily in a given language” (dictionary). Well, by that definition, I am fluent in Spanish, but there has to be more to it than that, right?

Yes! There is actually a good deal of debate about what it means to truly be fluent in a language. Some people think of it as being able to speak another language to the same degree as your native language, while others think of it as more of a spectrum. The International Center for Language Studies notes that if fluency required a mastery of all vocabulary in a language, it would be impossible to become fluent in any language. The typical educated English speaker, for example, knows about 20-30,000 words, which is a small fraction of the 273,000 words in the Oxford English dictionary. Of the 273,000 words included in the dictionary, only about 171,000 of them are currently in use. Simply knowing 1,000-3,000 English words is enough to carry on a conversation, and it’s commonly recognized that advanced speakers know 4,000-10,000 words. Anything over 10,000 words puts someone on the same playing field as native speakers (ICLS).

In a language blog, Donovan Nagel writes why he believes fluency is a spectrum and the criteria he uses to assess a person’s fluency: “[t]hey’re able to use their target language to learn more target language” (Nagel). This is describing something I like to call “talking around a subject” so that a native speaker can understand what you’re trying to say. Allow me to provide an example: if I didn’t know the word “tiara” in Spanish, I would describe it as “something pretty that a princess wears on her head / algo bonito que lleva una princesa en su cabeza,” which would be enough for the person I’m speaking with to understand me and also inform me of the word.

With all of that being said, I think I’ve discovered that fluency in another language really depends on if you’re capable of easily and confidently expressing yourself in that language. Fluency is also something that isn’t easily defined as one thing, so I think a spectrum is fitting. Now that I understand a little more about it, I can say that I have reached some level of fluency in Spanish over all these years. ¡Espero que haya aprendido algo sobre su nivel de fluidez en otro idioma, también! (I hope that you’ve learned something about your level of fluency in another language, too!)


Bernoussi, Driss. “What Do We Mean by Language Fluency?” ICLS, 26 Feb. 2022, https://www.icls.edu/language-fluency-means/.

Nagel, Donovan. “Fluency in a Language – What Does That Mean Exactly?” The Mezzofanti Guild – Language Learning Made Simple, https://www.mezzoguild.com/what-is-language-fluency/.

“What Does It Mean to Be ‘Fluent’ in a Language?” Dictionary.com, Dictionary.com, 19 Jan. 2021, https://www.dictionary.com/e/fluency/. 


Daisja grins with a beach background, wearing a fluffy jacket and cool sunglasses.

Daisja Honorable


Daisja is a junior at Duke majoring in Neuroscience with minors in Chemistry and Spanish. She is interested in brain development and language acquisition, especially since she wants to work with children in the future and has been learning Spanish since 2nd grade. Outside of class, she enjoys playing guitar, FaceTiming her dogs, being a mentor, and helping welcome first-year students to Duke through orientation!

Elika Bergelson

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