In short, to "learn a new programming language" is the same as "learn a new spoken language" When you can communicate above the level of a total novice with "n

In short, to "learn a new programming language" is the same as "learn a new spoken language" When you can communicate above the level of a total novice with "native speakers/users" of the target language, you have "learned" it I can read tons of programming languages (ultimately, it's all manipulating truth tables to get massage data from one form into another) I can only write a couple (in any kind of proficient manner) My first exposure to FORTRAN77 was after learning BASIC, Turbo Pascal, and C++ (from a C/FORTRAN programmer) I brute-force translated from procedural FORTRAN77 into procedural C It worked: but it was ugly, inefficient, and didn't look especially "C-like", but that wasn't a surprise - idiomatic programming, like idiomatic speaking/writing, can't be fluidly converted into a different language without interpretation on the part of the translator A real-world example of this happened to me when I went to London England several years ago for a couple weeks on a project. One of the guys I was working with announced he was gonna go downstairs and light a fag. As an American, I found the cavalier nature of this declaration shocking! Until I asked him what he was actually going to do. In England, "fag" is slang for "cigarette". In the US, it's [vulgar] slang for "homosexual". When you can idiomatically communicate/read/write (even in limited form) in the target language, you have "learned" it