As an adjective:
* She is fluent in Spanish. (Describing someone's ability in a language)
* His writing style is fluent and engaging. (Describing a writing style)
* The presentation was fluent and informative. (Describing a presentation)
As a noun (less common):
* The speaker's fluency was impressive. (Describing a person's ease in communication)
* They achieved fluency in French after a year of study. (Describing the result of language learning)
You can also use "fluent" as part of a phrase:
* She speaks fluent English.
* He has a fluent command of the subject.
* They are fluent in both spoken and written English.
To provide a more specific sentence for "fluent," please give me some context or tell me what you want to say.