(I'm a System Engineer, not a programmer) - Don't you need to understand a language, to understand a program, in order to be able to rewrite it to a different language?
I'm a native spanish speaker. When I hear Italian or Portuguese I can understand most of it, butnI wouldn't be able to formulate a proper sentence.
The same happens with programming language, you can get the semantic without knowing the syntax just because you know how to program, and of course, you can read specific syntax documentation (the dictionary) when something is not clear.