What does it mean to "know a programming language"?

Question

Programming

When can a person confidently say in an interview: "I speak / the name of the programming language /"? Is there some universally recognized minimum of knowledge that allows their carrier to say so?

Answer 1

Own - when you know: how to manage the architecture of building an application, change it if necessary, know 100% of the existing ones and by heart / from memory 75-80% of frequently used base classes and functions without documentation and you can write on it only occasionally looking into the documentation of any application medium difficulty.
Those. to master - to know how to achieve the target result in 75-100% of cases in the minimum time.

Answer 2

usually adequate people say "I speak /the name of the programming language/ at the level of ..." beginner, junior, mid, senior, etc. And the requirements for these levels, in principle, have already been formed, they can be found on the Internet.

Answer 3

If in doubt, you don't own it.
There are, of course, formal tests, but they are not needed.

Answer 4

See the specific language, its standards and specifications. Everything is simple.
Example:
Java Junior - {list of what you should know for sure}