I'm interested in languages and linguistics, can speak a few languages (English, French, Mandarin, some German, Japanese, and Esperanto) and would like to eventually learn more (Japanese, Spanish, Russian, Arabic, maybe Italian).
So, are there any fields of linguistics that would be particularly useful for learning languages, and especially, their grammar? (and give me a broader understanding of linguistics along the way) And any resources (books, websites - a Wikipedia page?) for those?
There are a few books referenced on Resources comparing grammars of different languages that seem interesting, but I don't know enough to really evaluate them.
Language typology looks like it could be useful, though I'd rather avoid discussion of features that only appear in a few uncommon languages.