[Eric]

The dilemma is: time and priorities. As English is my mother-tongue, I can theoretically swan all over the world without picking up anything of anyone else's language. But I am satisfied that I have insights. While I am ashamed at the number of languages I have merely dabbled in, the few I've learnt well are satisfying.

Language learning is a slog. I enjoy it in bouts, but I do tail off. And building up vocabulary varies from topic to topic, as Max suggests. If you can read a novel in, say, German, you can't necessarily read a contract, and vice-versa. Specialist vocabulary is one thing, all-round everyday vocabulary, mixed in with some specialist words, is another. And language evolves over time. You have to be sensitive to regional and archaïc features when reading literature. But a management report written within the past five years will have a fairly standardised vocabulary (assuming the manager writing it is literate and consistent!).