Fluency (noun)

The ability to speak or write a language easily and well.

Origin:

From the latin word "fluentia," meaning a flowing or ease of speaking.

Examples:

1. She had a fluency in Spanish that impressed her classmates.
2. He had a fluency in multiple programming languages which helped him land the job.
3. He was very nervous about giving his presentation, despite his fluency in English.
4. Her fluency in French allowed her to communicate easily with her clients.
5. The teacher was impressed with the fluency of the children's reading.