Reading and writing, yes. But my daughter says learning to *speak *Japanese was no harder than learning to speak German.
As for myself, I found Spanish pretty easy, and much easier than French.
How about something close to English with an easy grammar? (I am tempted to say the closest language to English but that is probably wrong)
Tok Pisin, spoken in Papua New Guinea.
Examples: Tok Pisin phrasebook - Wikitravel
As someone who has studied both, I have to call BS. Japanese is kind to students in terms of pronunciation and regularity of grammar. But it is only easy in the sense of “Hey, this isn’t so bad for a language that isn’t remotely similar to anything I know and is also represented in three different alphabets of several thousand characters”. Even then, the honeymoon doesn’t last very long… once you get past the babytalk phase and have to learn some kanji and keigo, it gets very real very quickly.
That being said, language learning is easy for all children under the age of 10, so it’s best for all concerned if we disregard the ease with which the little brats pick up anything and everything like little sponges.
Thank you for all the excellent advice, folks. For now, it’s a toss-up between German and Spanish. German would be more fun, I think, insofar as I’m more interested in visiting Germany than Mexico (or Spain), and it’d be neat to know the language. But Spanish would be far, far more useful.
The actual answer is whichever language you will get a chance to speak most often. This is by far the most important aspect. Speaking a language with any proficiency is nigh impossible to do by books or Rosetta Stone alone. If you have a community college nearby to take classes from, really any Indo-European language will be fine. Spanish, Italian, French, or German will all be roughly comparable in difficulty as a first foreign language.
If you don’t have a place to take classes (or don’t want to), then perhaps there are groups in your area you could join to practice. When I took Italian 1 at Pitt, there was a twice a week group that met at a local coffeehouse to talk exclusively in Italian. The crowd ranged from Italian ex-pats to freshmen in Italian 1 who were getting extra credit.
If that fails, do you know someone fluent in another language who’ll be willing to talk with you in that language?
Actual practice and conversing is crucial to learning a language. Any Indo-European language will probably be easy enough. Learning Spanish from class or conversation + books will always be easier than learning something like Dutch which is nominally closer to English without the benefit of someone to talk to and listen to.
I believe it was The Story of English, by Robert McCrum, William Cran and Robert MacNeill, that identified the Dutch dialect of Frisian, possibly West Frisian, as the closest relative to English. They speculate that if the Norman invasion of 1066 had failed, England could very well have ended up speaking a language not unlike modern Dutch today.
Myself, I find the stereotype of the unilingual American to be rather unfair and have ever since personally encountering so many unilinigual Europeans in Europe.
Check out the language reviews on this site. Pretty subjective, but (IMHO) fun and informative.
There’s a similar list on How To Learn Any Language. 
Seconded.
I lived in Indonesia for a while and took a crash course in conversational Indonesian. Six weeks, two classes a week, 4 hours each. When I finished, I was able to carry on conversations with only occasional references to my pocket dictionary. At the beginning, I had to ask people to speak a little slower. My favorite phrase, and one that served as a tremendous icebreaker: Silikan, anda harus bicara pelan-pelan sekali, sama aku anak kecil (Please, you must speak very slowly, as if I am a small child). They would get a good laugh and slow down.
I got to the point where I was able to haggle with folks in the marketplaces. I loved that!
Well, if you want to learn German for the sake of knowing some when you go to Germany, the best language to study would be German. But in terms of ease, I would definitely say Spanish wins, and you’re probably more likely to have opportunities to practice.
IMO, there are two very nice things about Spanish: the grammar is straightforward, and it’s a Romantic language. If this is your first time studying a second language you definitely want something where you can do a simple comparison between how the structure of a sentence works in English and how it works in the other language. Spanish is pretty simple in that respect.
If you do decide to go with Spanish, my advice would be to throw some Latin in. Memorizing Spanish vocabulary will give you Spanish vocabulary. Memorizing Latin roots will give you a foot in the door for all Romantic languages. If you know your roots and five years down the road you decide you want to learn French, or Portuguese, or Italian, or any of the smaller languages in that family, it’s pretty much a matter of details.
Waffle Decider nailed it.
And you’re missing a huge opportunity if you pass it by, for several good reasons;
Indonesia is a ton of fun to visit, Bali, beaches, jungles, ruins, the shopping is to die for, (clothes, leather goods, wood/stone carvings), the food is delish and the natives are friendly.
Bonus points for the fact that Behasa Indonesian bleeds into Malay quite significantly, so you kind of get a two fer.
Let me show you exactly how easy- Anak = child, children? Anak anak. What’s not to love?
As if that’s not enough, this language uses the squared notation grammatically. Children, on signage is often written anak with a little two, (sorry don’t know how to do that on a computer keyboard), up to the right.
Spanish and German speakers are a dime a dozen on this side of the pond.
I’m just saying, think about it.
I don’t think it has to be a superscript. Indonesian forms plurals by repeating the noun. So “gado” is vegetable, and the plural is said “gado gado” but written “gado2” (and delicious in an Indonesian or Malaysian restaurant).
Can you drink the water there?
I wouldn’t recommend it, but bottled water is easily available and everything is real cheap compared to here. Oh, and I forgot to mention volcanoes too!
Mmmm, Gado Gado!
double post, ooopsy!
I didn’t say anything about reading and writing, and was replying to someone who was specifically referring to the spoken language rather than the written language.
*This may have been true for your daughter, but it is not the norm. Not unless she was referring only to basic pronunciation – there aren’t many sounds in Japanese that would give a native English speaker trouble, and it may be no more difficult (or even easier) than German in that regard.
I can second this. I took a couple intro-level Japanese courses in college and was surprised at how quickly I could pick up the basics. The basic sentence structure is fairly simple (although different from English), there are no gendered nouns to worry about, and the word pronunciations are straightforward. Even learning Hiragana and Katakana (basically the Japanese alphabet, different from kanji, the characters borrowed from Chinese) was surprisingly easy - I actually found it easier to write/read than to speak/hear. Plus it’s loads of fun to bust out at a sushi restaurant!
Whoa, I disagree. Russian, Farsi, and Hindi are Indo-European languages. For a native English speaker, Spanish, French, or German would be massively easier than any of those.
Nepali is another language that is not difficult to learn. It’s related to Hindi and like Hindi is a member of the Indo-European group of languages. Pronunciation is pretty straightforward, and I’ve known people who could get by easily with only a month or two of intensive study.
Of course, it’s easy to get by in Nepal with English, but learning Nepali would be cool, and Kathmandu is a great place to hang out.
How cool - thanks! They’re really fun to read.