Here's why:
* Satisfied refers to a feeling of contentment or fulfillment, often in response to a need being met.
* Fluent describes the ability to speak or write a language smoothly and easily.
These words are from different semantic fields and don't have a direct opposite relationship.
Possible antonyms for fluent:
* Halting
* Stuttering
* Awkward
* Hesitant
* Ungrammatical
Possible antonyms for satisfied:
* Dissatisfied
* Unfulfilled
* Unsatisfied
* Discontented
* Grumbling