We can make an analogy to programming languages. The reduced vocabulary (if any) from learning two languages at once can be likened to the fact that when you learn two programming languages you will probably not be familiar with as many modules from each language that you learn, whereas focusing on one programming language would allow you to deeply learn all the modules available. However, you would still fully learn the syntax and most of the core features of both programming languages. In contrast, the analogy to what George Orwell was talking about would be removing features from the core language to the point that it is no longer Turing-complete, and is only capable of expressing "approved" programs. Kind of like HQ9+[1], only instead of "hello world", quine, and 99 bottles, it's "The government is great", "I love the government", and "All power to the government". The plus can still increment the accumulator, but the accumulator represents how much you love the government.