What is the most efficient set of languages needed to easily become proficient in any language?

Question

I’m not familiar with the terminology to ask this question properly, so I’ll do my best in laymen’s terms.

I’m a native English speaker, so I find certain elements of other languages particularly difficult to hear/discern and to pronounce. For example, I can’t roll my R’s. I also find the different vocal tones of a language like Vietnamese very difficult both to discern and repeat, and many words from Slavic languages are difficult for me to pronounce.

In a hypothetical scenario, say you had an English-speaking child and you wanted to teach him a set of languages that would make him competent at both discerning and making all the vocalizations needed to easily become proficient with any major language. By “major language,” I’m excluding little-known local languages. I’m also ignoring reading and writing. What might be the most efficient (i.e. minimum number) of languages for him to learn?

Answer 1

Differences between languages
Phonetical differences are not the only difficulties that one encounters when learning a foreign language: there are also substantial differences in * Grammar (like noun inflections in Slavic languages or Hungarian/Finnish, different use of tenses in English and romance languages, different conjugation patterns in Arabic, etc.)

• Vocabulary - English is close to Germanic and Romance languages, but have little in common with Slavic languages and almost nothing in common with Arabic or Chinese
• Writing system - that might be an easy one when it comes to learning Cyrillic or Arabic script, but a substantial one when learning Chinese or Japanese.

Teaching a child
I hope that you are not discouraged by what I wrote above: children rather early learn to recognize the phonological system of the language spoken around them (that is they develop ear for the phonetic differences important for this language and.) It is even claimed that French and German babies cry differently. Thus, exposing a child from birth to a second or third language is very beneficial, if they want to study languages in future - just having one's ear capable to recognize differences between two or three languages is helpful for learning other ones. Important thing here is that this should be authentic sound - speaking German or French with American accept is not likely to do the trick.

Note that speaking a language around the child does not guarantee that they will know this language (i.e., popular attitude one parent - one language is largely a myth). The reason is that the child's exposure to different languages is likely to be different: if one parent speak to the child in French, but everyone else in school, family and street speaks English, they will likely speak only English, although they may understand some basic French and have their ear tuned to French sounds (i.e., they will acquire some passive knowledge of language). The situation is different, if one language is spoken at home and another outside or if the family often spends vacations in a country where the language is spoken. One crucial element is the language spoken by parents - if the French-speaking parent speaks English to their spouse (e.g., because the latter doesn't know French) it would be hard to Force child speak French.

Thus, teaching more than one or two second languages is practically difficult - E.g., one could imagine a situation with three languages: one parent speaks French, the other German, but they live in the US. Provided that they often see their French and German family this could work. I do know people who grew up speaking more than three languages, but they usually come from countries where multiple languages are spoken around (like India).

TL;DR: It is beneficial to expose a child early on to sounds of a foreign language. More than two-three languages is usually impractical. They however will have their ear tuned to appreciate phonetical differences beyond their mother tongue, which will facilitate learning languages in future.

Answer 2

Short answer

Picking this or that language will never make a big difference. It's all about not losing your infant-ears.

Long answer

In order to get to your target which you stated as

make him competent at both discerning and making all the vocalizations needed to easily become proficient with any major language

By personal experience I can say with 100% certainty that, it would be MUCH MORE HELPFUL if he first spent his time trying to get perfect with the foreign accents of his first language i.e the one that he already speaks. Like being able to sound totally American even if he was born and raised in the UK and sound British despite being raised in the US. Only if he can do that will he become a candidate of achieving that target.

As for what makes it difficult to get familiar, you said,

I’m a native English speaker, so I find certain elements of other languages particularly difficult to hear/discern and to pronounce.

Well yes, we are all aliens in this world and humankind has only recently started trying to become globally local on the planet. Consequently, the more people become aware of the greatness of being a polyglot and discover the magnificent opportunities that monolinguals will never get, the more the aspiration.

But we are limited by the average duration of human lifetime. To understand the idea, let's imagine that you were born in the land of flutists and you were raised playing only the flute and hearing nothing but the sound of the flute. And then one day you discover the world of guitarists and hear interesting things about the land of pianists and finally start thinking about migrating to the country of harpists and becoming a harpist yourself.

Learning languages is similar. By personal experience I can surely say that being able to speak Japanese with native fluency provided only a negligible tiny amount of help in learning Korean later even though they belong to the same language family. The only way to shorten the time of learning is by listening to the world as if you still were a little child.
Concisely, "One must learn how to do that (i.e. keeping your infant-ears active) either before or along with learning this or that language."