articulacy, facility, ability to speak or write … easily and accurately; 

command of 

Synonyms of fluency in English: a job that calls for verbal fluency 

eloquence, articulacy, articulateness, expressiveness, communicativeness, coherence, cogency, intelligibility, comprehensibility, lucidity, vividness, persuasiveness, glibness, volubility 

fluidity, flow, smoothness, effortlessness, ease, naturalness; 

grace, gracefulness, elegance; 

regularity, rhythm, rhythmicity