No reason not to start learning now, but good reason not to expect native-level fluency.
"Do younger beginners do better because their earlier start gave them more learning time, or because they learned faster in early years? It can be hard to tease apart these two questions. But testing a huge amount of data against a number of possible learning curves allowed Mr Hartshorne to do precisely that. Many previous researchers had posited a drop-off at around puberty. The new study found it to be rather later, just after 17.
"Despite that later cut-off, learners must begin at around ten if they are to get to near-native fluency. If they start at, say, 14, they cannot accumulate enough expertise in the critical period. Unfortunately, 14 or so is precisely when many students, especially in America, are first introduced to a new language. (Even worse, this is an age when children are acutely sensitive to embarrassment in front of peers.)
“Children who start at five don’t do noticeably better than those who start at ten over their lifetimes. But there is still reason to begin in the first years of school, as in Denmark and Sweden. Because mastery takes a long time—perhaps 30 years until improvement ceases—those who begin at five and are obliged to read and write English at university will by then have made much more progress than those who took the plunge at ten, even if their level is roughly the same by 40.”
My children were veryyoung when they arrived and soon learned enough quickly to integrate and then more and more automatically as they were not given any special help nor anyone who could speak english did. My catalan grandson is picking up english from his dad and me which is what his parents want but its hilarious with many french words in english only, he dosn’t like the french equivalent and he is getting an english accent too when he is around me but not the french grandparents. My husband just made up his own version of french if he did not know the words, he would say the english word and put a french accent on and it worked quite often and made him a lot of friends who loved his attempt.
At age 6 I spoke impeccable French and German (at the level of a 6 year old of course). Sadly my grandparents died and our household stopped being trilingual. My skills took a nosedive and my German has never recovered.
Interestingly my sisters who are older than me have a more natural facility for languages now as they had more years of immersion,
Yes, silly isn’t it? My wife’s eight year old niece stayed with us this summer while her folks attended a conference in Grenoble. She lives in Montreal so is fluent in French (or something approaching it, some might say ) and English (via her dad) and Italian (via her mum). It’s lovely to see her switch effortlessly between the three, even in the same conversation. My daughter’s French is very good due to her Francophile mum working with her from an early age.
In my experience, both, without a doubt. Many years ago I lodged in Bedford with a family, father Polish, mother, Italian, 2 very young children, fluent in 3 languages. Much of the time, as the parents were not that good (what a courtship that must have been ) at other than their own, the kids translated between them. Then there was me trying to communicate with my Nor’n Ir’n friend in the same household. What a cacophony.
She lives in Montreal so is fluent in French (or something approaching it)
Made me laugh that, we have a Quebecois living in our village and I asked Christelle, our French aide, if he spoke French (of course I knew he did) and she grimaced and said ‘a peu pres’.
Thank goodness my education in FR started the moment I arrived at pre school, aged just short of my 8th b/d.
The FR master was extremly good. By the time I left I had written what amounted to a FR grammar book. The vocab book we used was, by coincidence, the very same that was used by the school I went on to, written, as it happened, by an ex-head of same.
Eight years of FR lessons, +/-3 hrs/week, for 8 years. Apart from a week or three here ‘n there on photo shoots or battlefield guiding, it wasn’t till I got off the ferry 3 years ago tomorrow that I needed FR full time but those early years’ learning have stuck.
French people compliment me on my FR. They are being v kind. I think they like the idea that I just go for it and can do ‘R’ correctly.
As children, both my nephews (who were born in England) effotlessly flipped between Basque and English, which was very impressive but what was more so was that even when they were very, very young, they knew which members of the family to address in English.
Interesting NY Times article which reframes French speaking again - not too surprising if one is a regular Fr24 viewer, but food for thought…
) and English (via her dad) and Italian (via her mum). It’s lovely to see her switch effortlessly between the three, even in the same conversation. My daughter’s French is very good due to her Francophile mum working with her from an early age.
) at other than their own, the kids translated between them. 
Then there was me trying to communicate with my Nor’n Ir’n friend in the same household. What a cacophony. 