Assuming people will need to have some language skills in future, other than english, to have an edge in their career…
What will you advise your child and why ??
Were we still in Canada, it would be French. Since we live in the US now, it will be Spanish. My older son is taking Spanish in school, and we will encourage him to become fluent. We would also like to become fluent. Spanish is the unofficial second language in the USA.
My French skills have greatly eroded, as I have nobody to speak it with. I’d like to pick it up again.
Mandarin. I strongly believe that by the time my kids are my age (mid 30s), people who are bilingual English/Mandarin will have distinct advantages in the world.
English 
Not all of us live in English-speaking countries, you know!
I agree. Careers in government/diplomacy, business, import/export, economics, and others would be greatly enhanced by knowing Mandarin. I’m sure there will be some good military intelligence or CIA positions available as well.
Well, The Nephew(s) will definitely be learning English Depending on what schools they go to and how the educational system evolves, they may also get Latin (one year), French or German before getting to college.
For someone from an English-speaking country, I’d say Spanish, French or Arabic. They are spoken in many locations, so they’re good for personal travel as well as for civilian and military careers. Mandarin is the shiny-shiny new thing now but it’s a bit too much putting all your eggs in one basket, you know?
French. I don’t care about practicality, I care about their heritage.
Icelandic. Same rationale as Antigen. Then possibly some form of Chinese or Japanese. Spanish only gets you ahead in the states if you want a job in the service industry.
Latin. I studied it for a few years at school and it was great help for English. Whereas most of the French we were taught has been forgotten, I still remember loads of Latin vocabulary, and it continues to help.
Besides, learning Latin consists of translating Tactitus’ account of the Roman assault on Anglesey. Learning French consists of telling your classmates how you hate hoovering your room: yawn.
If a modern language was really necessary, probably something from the Indian subcontinent. Everybody focuses on the Chinese, forgetting that India is a burgeoning superpower, too.
I’m going to tell them (have told my son, will tell my daughter) the same thing my mother told me: Latin. And I expect them to ignore me the same way I ignored her and to later regret it the same way I do. (Especially as I moved deeper and deeper into medical fields. Anatomy would be a SNAP if I knew Latin!)
Although continued conversation with my son has led me to believe that German is probably the best choice for him - he’s leaning towards engineering/mechanics sorts of things, and some fluency in German will probably be useful for that. Unless he decides not to go to college and ends up on the fixing end of consumer goods, in which case Spanish would serve him well here in Chicago.
Noone, Yes I know, but I asumed English would be a sort of given, since most countries, do encourage at least higher eductaion in English ( per my limited knowledge).
I do interact with an Israeli company, and the global sourcing guy iss quite good with english. ( he has to be 
)
OK, OK
Serious answer – Israelis really should probably learn Arabic. If only in order to better understand the people we’re living amongst. I regret having taken French as a Second Foreign Language, and it unfortunately seems like my children are going the same route (it’s really the path of least resistance when you already know at least some English; and I try to choose my battles with them.)
I will encourage Spanish. It is not too difficult and would prove useful in life if they pick it up. I had Spanish & Latin. I really liked Latin and it did help tremendously on my verbal SATs and for understanding, many root words, but I wish I was better at Spanish and had kept it up.
**OneCentStamp ** mentioned Mandarin, which would be a great choice, but unless one of my kids shows a high aptitude for languages, I would just suggest Spanish.
Jim
Every English-speaking Canadian gets exposure to French.
The next choice might be the language of one’s family or ancestors; I’ve met so many people who never learned the language of their grandparents and bitterly regret it. And the language of one’s lover is up there definitely. Then there’s languages one might use professionally in the short term.
For non-family, non-work third languages in North America, I’d say it’s a tossup between Spanish and Mandarin.
Of course, there are other languages with unexpected advantages. Esperanto, for one.
And what of the languages one is simply attracted to? For example, I’ve wanted to take Japanese for years.
We’re doing Latin first. Later one, I’ll let her pick her own modern language to study (if she’s good at languages, I’d probably suggest a Romance language first and then something more out there). I was very skeptical of Latin, being a modern person who had never learned any at all, but I’m a complete convert. I’m learning so much useful stuff, and we’re still at the baby level! (I also did some on my own over the summer to get ahead a bit.)
I learned Danish myself, and then a bit of German and a good deal of Russian. None of them have been particularly useful, but lots of fun! I’d like to learn some Hindi sometime.
I’d agree that a kid with access to relatives who speak a language should learn whatever that language is, it’s just that we don’t have that. My brother is a German professor married to a Russian woman, and their kids understand 3 or 4 languages (German, Russian, English, Polish) and he wants to start Latin now that the oldest one is 4.
dangermom, can you recommend any resources for homeschooling Latin?
For heritage:
I’ll probably encourage our kids to learn Spanish fluently, because of their heritage–my mother-in-law is Puerto Rican, and speaks it routinely with her family, but her kids never learned it. I think it would be nice for our kids to learn it and be able to investigate that side of the family if they ever wanted to. My husband isn’t really interested in his heritage on either side of his family, so he’s neutral on it. I’d love to know more about mine, but there’s really not much data to go on, so I want my kids to at least have the option, y’know? My side of the family has been in Kentucky and West Virginia since anyone remembers, so maybe a hefty southern accent? Seriously, I plan on passing down some hillbilly phrases. That falls more under culture than language, though.
For basic education:
I’d also suggest that they learn either Japanese or Mandarin, because of the potential benefit to their careers, and because a langage based on such a different system of writing and grammar would hopefully engender curiosity about the world–cultures, psychology, history, linguistics, something.
I’d recommend Irish (Gaelic). It’s hard to learn though. It has very little practical application but is a beautiful language means your child can have a secret conversation with other Irish speakers anywhere it goes.
For practical use, I’d go with Spanish, Arabic, Hindi or Mandarin.
The schools around here offer French or Spanish. Maybe, in high school, Latin (but I don’t remember it offered when I was a kid). Spanish has many uses, even outside the service industry. French, on the other hand, not so much.
I may have an easier time getting them to pay attention in Spanish than my parents did getting me to care about French, as we vacation in Mexico quite a bit. I think they both have bilingual friends, so they already know more Mexican than I ever learned French.