Language for the purpose of study, travel and maybe work in Europe.

Hi! Fellow Indian here, albeit a native speaker of English. The one piece of advice I have for you: improve your English. Seriously. A lot of us fall into the trap of thinking English that's good enough for our purposes in India is good enough for studying abroad. It's not. I'm a native English speaker (I've been speaking it since I was three) who spent most of her schooling in elite private English-medium schools. My American classmates at my current school still have a little trouble understanding my accent. And I see how my classmates who are from countries where English is not their native language struggle to produce quality academic writing, even though they're by no means unintelligent. So if I were you, I would focus on getting my English from merely 'proficient' to 'excellent.' (If you don't already read National Geographic magazine, I recommend it, it's brilliant and really helped my grasp of the language.) Honestly, unless you plan on staying weeks and weeks someplace that doesn't speak English, a phrasebook and a few words in the local language is fine. My German is limited to 'Guten tag,' and 'Bitte' and 'Danke' and I got along fine in Frankfurt. Ditto Lisbon, and I speak even less Portuguese. So figure out where you're going to be, and then learn that language. It'll be of more use in the long run.

Netherlands, Germany, Sweden Post graduate studies in these countries, and many/all Universities in your other listed countries, is going to be in English. And, given many of your teachers will speak English as a second language, the best way to really get the most out of your education is to improve your English so it's better than 'proficient'. How well the international staff and students do at the Universities I've worked at in Ireland and Germany depends pretty directly on their English language skills more than any other parameter. As for travel, English is the most widely spoken language and you will be able to get by in every place you've listed with it to at least some extent. So again, having that as good as possible should be your first step. Then for getting jobs in software, there are many software jobs in Western Europe in English. However, having even some understanding of the local language will always be helpful. Knowing German in France, for example, isn't going to help you, but knowing it in Germany will. So learn the language of whatever country you end up in. But it's also not always necessary, particularly if you're not able to learn it well enough to speak as your primary language (in which case you're back to English). If you don't know what country you'll end up in the French and German are the most widely spread. Pick which part of Europe you're likely to go to then choose whichever is most applicable. When you're looking at regions consider that moving from French to Spanish or Italian will be easier, or from German to Dutch or Swedish, in case that helps you decide between the two. Then when you get here it may be that you've learned the wrong one or whatever. Don't worry about it, just start over with whatever ends up being useful and use the one you learned while travelling. Which language is less important than just choosing one and getting started.

If you're based in Germany or Switzerland, I'd say German is worth a serious effort; it is the first language of more Europeans than any other and it has first rank importance in music , literature and other fields. Finnish, Swedish, Dutch, just not in the same league. So if you're not in Germany, you probably want a Romance language instead. I do not think French is the automatic choice it once was, but unless you're particularly keen on Renaissance stuff, it still probably beats Italian. Spanish is a contender, especially given its world position, but for you I don't think it overhauls Italian. It's true you can get by with English, but you'll get a much better appreciation of European culture if you don't see it from a monotonously Anglophone perspective. Of course you'll want to pick up a few basics in the language of any country you visit; it's handy, polite, and not difficult.

I just want to understand the various reasons people have before they start learning a language. Well, what was your reason to start learning English? I'm on a few language-learning forums and "what language should I learn" is one of the most commonly asked questions. It is also the most unanswerable because no one else can want something for you. One important factor is that a language outside the context of its culture is like a car with no wheels. No one can make an argument for why you should learn German, for example, if you otherwise have little interest in its culture. As purely pragmatic advice, since the country where you will be living is where you will be spending most of your time, learn that country's national language. It would make no sense to decide upon French based on advice here if you ended up living in Spain. So, I think your question is premature at this point.

I think you maybe have a misconception about how widely European counties speak each others' languages. Speaking Italian is only useful in Italy, speaking Spanish only helpful in Spain (and outside of Europe). French is spoken in Belgium, Switzerland and a few others. German will be understood in many Scandinavian countries, though not as well as English is. German is actually rather useful in Eastern Europe (Hungary, Slovenia, Poland, Romania) where it has retained the lustre of the language of culture in the 19c and people have learned it as a second or third language. I have used German to buy train tickets in Budapest to Romania, for example, because you aren't going to understand a word of Hungarian. Knowing English and German you can get the gist of Dutch and most Scandiavian languages (Finnish is its own beast, of course), too. For Southern Europe, I'd recommend either French, because it's the language of culture people from these parts who weren't taught English as a second language learned, or Italian or Spanish since if you know them, you can get the gist of a lot of stuff from Spain to Romania in the same way that if you know both German and English, you can sort-of interpolate Dutch. But as has been said, French is useful if you want to go around Africa, and Spanish is useful if you want to go around Latin America. Oh, and learning a bit of Latin wouldn't be a bad idea, since it is the trunk from where Romance languages grew. It's just that it has few practical uses if you aren't into 500 year old+ books or don't have the urge to read the inscription on that medieval bridge.

I think you maybe have a misconception about how widely European counties speak each others' languages. Speaking Italian is only useful in Italy, speaking Spanish only helpful in Spain (and outside of Europe). French is spoken in Belgium, Switzerland and a few others. German will be understood in many Scandinavian countries, though not as well as English is. Honestly English is the most widely spoken second language. I speak German, Spanish, and bits of Italian and French, and I have never found any kind of use for them in other European countries - if I don't speak the local language (and often even when I do) people speak to me in English. I would personally learn the language of the country you are going to, as that is likely to be of most use plus you will have a chance to practise. If you want to learn a language just for fun then learn French as it is a Romance language and likely to be helpful for learning others, but don't expect beginner French to do much for you in Spain or Sweden.

I mean people are basically going to say French or Spanish. Well no not really. Those seem to be the default choices in the US, but in the English speaking nations of Europe, German is at least as common for second languages, and I think more common than Spanish. What European language should I start learning so that I can enjoy company of people, my interests in arts, and travels? For better or for worse, English is the shared second language of Europe. Were I picking another in terms of use, I'd say French.

The only way I would be worried about learning a specific non-English European language is if you end up moving to a country where English is not widely spoken among everyday people. In Scandinavia, the Netherlands, and possibly even Germany, English will probably be enough and you would only learn the local language out of enjoyment or to integrate better with the local culture. If you end up in France or Italy (not sure about Spain?), however, you are going to find a lot of people who are monolingual in the local language, and not knowing any French or Italian at all is going to make life difficult. So, I don't know, maybe default to French or Italian, and if you end up in a different country, well, hey, you studied an interesting language for a while, so, OK. If you are really seriously not sure at all what country you'll end up in, pick French, because it's much more widely spoken than Italian. If you are very seriously considering Italy, pick Italian, because seriously a lot of Italians speak Italian as their only language, and not speaking it will be a huge problem if you move there. Maybe not in your graduate studies, but certainly for basic things like figuring out a bus route or talking to the neighbors. If you are very serious about Spain, I would do Spanish, though I don't know that Spain is quite as monolingual as France and Italy tend to be.

Yes, I would say German. You are looking at living in Germany, and from experience, many many many Germans travel around Europe, so people in the service industry tend to have it as a second language. Either that or a English, which you already know.