What is having a good working knowledge of something?

From Longman Dictionary of Contemporary Englisha working knowledge of somethinga working knowledge of something enough knowledge of a system, subject, language etc to be able to use it or to do a particular job A good working knowledge of the building regulations is necessary for the job.

How do you say working knowledge on a resume?

If you are truly an expert, don’t be afraid to say it. “Working knowledge” basically means intermediate experience, and just say “Basic understanding of…” if you are a beginner. You’ll also notice that I listed some character traits along with technical expertise.