biegłość in inglese:

Her proficiency in English rapidly improved.

German instrumentalists were known for both their strong performance proficiency as also their skills as improvisers.

A competency is used to gather proficiency level and years of experience of a candidate in order to find the best candidate for a job.

The letters STEP stand for the Society for Testing English Proficiency.

On a scale of 1 to 10, please rate your proficiency in the following languages.