Speaking as someone who has studied (to the point of having useful ability with) multiple languages, I can certainly attest to the benefits in the general case. When you're talking specifically about technical material, though... you need to have realistic expecations. Since it seems that you have never before studied a foreign language (at least, not to any significant extent) you may not appreciate how very difficult it for many people to acquire this skill after the age of 11 or so. Even if you find that you do have a knack for languages, there is an enormous (and I mean ENORMOUS) difference between the amount of effort required to obtain basic reading skills and true fluency. Depending on the language, it may be easier to learn to speak it than to read it. I think you should very carefully consider just how much time you think you would be spending in this effort. With that in mind, I offer a (very) brief guide to language complexity: Spanish : Doesn't get much easier than this. Has case and gender, but it's still a romance language using the latin alphabet. Grammar is easily relatable to English, and vocabulary can be acquired rapidly. It's also fairly regular in terms of both grammar and spelling. Not of much use as a technical language. French : Somewhat harder. Like Spanish, has case and gender; add to that an unbelievable butt-load of tenses (13, I think) of which you'll only ever really need four or five. Like Spanish, it is a romance language, so grammar and vocabulary are easy for an English speaker to acquire; also fairly regular (although not so much as Spanish), more useful as a technical language. German : Somewhat harder yet, I think, but not everyone agrees. Has gender, and is very heavy on case. Spelling can be highly irregular, although not nearly so much as in English. Case issues complicate grammar and can boggle an English-speaker's mind. Historically regarded as a language for technical documents. Russian: I'm married to a Russian speaker, and I can tell you that you are leaving the safe harbor of the romance languages behind. Russian has case, gender and (God help you) declension. Grammar rules are very complex, but fairly regular;. The alphabet is Cyrillic, of course, but it's not much harder than the english alphabet to learn, and the spelling rules are much more regular then those of English. There's lots of technical material in Russian that might be of interest to an Engineer, but the amount of study required will be significantly more than for the preceding languages. Japanese : we're starting to drift into the realm of masochism here. Japanese grammar is simple and highly regular, but counter-intuitive to a speaker of English. You will have to learn approximately 2,000 individual pictograms, just to acheive basic literacy, plus another 2,000 to 5,000 pictograms (Kanji) pertaining to your technical specialty. It's not too difficult to learn to speak Japanese; learning to read it is a bitch. Could be worse, could be Chinese... Chinese (Mandarin) : If you go this route, you are both maximizing your value and (probably) guaranteeing your rapid collapse into insanity. I can't speak too much to this language; unlike the others, I've never actually given it any formal study. It's grammar is supposed to be fairly regular, but it's poly-tonal (same phoneme has different meanings, depending pitch), which is hell on anybody who wasn't raised with it; lots of sounds that are very difficult for foreign speakers to distinguish. On the reading end of things, you will have to master about 5,000 pictograms for literacy, plus another 3,000 to 5,000 for technical literacy within your (technical) specialty. You don't even want to know what's required if your specialty is in the liberal arts. I hope this is of some help. As a general note, an English speaker with a moderate disposition towards acquiring new languages can gain useful skills in any of the romance languages via self-study. For any of the others on this list, the self-study approach is suicidal.