[SOUND] So, the interesting question people ask me is, Should I teach my child a second language at birth, at three, at five, at eight? And I always respond, it depends on what you want the outcome to be. One interesting literature is that one what I call orphaned languages. Right? Languages that people hear when their young and then don't hear again for many years. I actually think I experienced and orphaned language, when I was a child I learned Spanish and English simultaneously. For about a year I had a Persian babysitter that my mom says I would talk to in Persian. I don't remember any Persian, I don't, have never tried to relearn it. But an interesting thing happened to me when I was about seven or eight. So there was a very famous artist in Mexico, in Latin America called Roberto Carlos, Joberto Carlos if you want it in Portuguese. And he was more famous in Mexico and Latin America than he was in Brazil, his native country. And so, I learned about this, his music was all over the radio. I came back to the U.S. after spending time with my grandmother and my mom's family, during the summer. And, I bought a record in Spanish of Roberto Carlos and I sang to it. And a few months later my dad, again, took us to look for records and he found a Portuguese version. Right. So it had a slightly different cover, it was white. And he bought it for me. And my dad used to listen to the Portuguese hour on the radio every day it was about the time that we drove home from school. And so he knew about Portuguese and he thought, well I'll just buy this record for my son. And, of course, I started singing to it and I sang to it maybe for about a year or two, have recordings of myself singing to these records, and then after about two years of age, this may be around the nine to ten year of age, I grew, had other. Musical interests and I stopped singing to this record. Now, at the age of 20 I went to Brazil for a year. And when I initially arrived I had this very thick accent, and if I listen to the recordings of singing to Roberto Carlos in Portuguese, I hear pretty thick spanish accent when I was about six or seven. I had that thick accent at 20, but over time it peeled away, and by the end of two years, people couldn't tell I wasn't a native speaker. Now you could say, well it was because of English and Spanish, right? I had these larger sets of phonemes, maybe my phonemic space was open longer, and that's probably did have an influence. But, a few years later when I came back from Brazil and I was singing a lullaby to my son, I sang one of the songs that I had heard on that record from Roberto Carlos. And when I sang the lullaby the accent that came out was a North Eastern Brazilian accent which was Roberto Carlos's accent. And not my Paulista which is from São Paulo, which is in the south, and it's a much different accent in Portuguese. And so, when I sing the song, the accent that came out was the accent that I'd heard as a child. Not the one that I had learned as an adult. And a light kind of went off in my head, and I said that's really interesting. Somehow the sound that I'd heard as a child got recorded and came back in this song, but many years later. And I call this phenomenon, the orphaned language phenomenon. Wilder Penfield is very famous for his work, on mapping out the brain through stimulation. Had his children taken care of by a German speaking lady. His idea was that it would be easier for his children to relearn German as adults and in fact that was true. He observed that his children seemed to be able to learn German with less of an accent. Because as young children they've been exposed to German, and then taken care of by German speaking lady. There has been research on this question, looking at whether exposure to a language early in life remains and provides some advantage to people even when they don't use that language any more so in work by Terry Yao. And for colleague O what they've looked at is they've looked at a group of people who have overheard a language and then to interview at least claim to not have used it quite as much. Or maybe used it a little bit when they were young but then been effectively cut off from it as they became older. In one particular study they looked at English speakers who'd been exposed to Korean when they were young. And the question was, when they took Korean as adults in college would they have some form of an advantage in this language? Now, what they found was that. Those who'd been exposed to Korean could actually detect speech contrasts that existed in Korean and not English better than English speakers who were taking Korean for the first time. Interestingly they also found that those who had spoken some Korean had, had a re, at least itself report from their family members. Used Korean to some extent, could also produce it better, and they spoke Korean as adults with less of an accent. So there does seem to be some advantage to having been exposed to a language as a child in terms of producing that language with less of an accent. A second study asked a slightly more complex question. O, and [INAUDIBLE] colleagues asked a group of Spanish over-hearers, so these were people who had grown up speaking English but had overheard Spanish as children, and. They looked at them as college aged adults and then looked at their ability to produce Spanish and in fact they found exactly what they found before with the Korean, overhearers. With the Spanish overhearers they found that they could produce Spanish with less of an accent. But then they wanted to ask a second question. Which is, did this exposure to Spanish somehow help them with grammar? Did it help them to learn some of the pieces of grammar that English speakers struggle with. Particularly what they wanted to look at was the way that Spanish marks both the plural, and also how it agrees with the determiner with regard to gender. So in Spanish, it turns out that for those of you don't know Spanish or don't know a Romance language. For those of you who do, I'll give you a very short explanation, it may be a little bit boring for you. So, for those of you who don't know Spanish or romance languages, Spanish marks it with an O and an A. You might actually have heard this from the former governor of California, Arnold Schwarzenegger who would say things like, no problemo, right, that's actually incorrect in Spanish. But he was picking up on this idea that no and problemo have to match, right? It's actually [FOREIGN] but that's a whole other side. We won't criticize him too much on his knowledge of Spanish since he's a German native speaker. In any case, so you have to make thing agree in Spanish so if you say [FOREIGN] [FOREIGN], right? That's correct. But you can't say [FOREIGN]. You have to say [FOREIGN]. And things get a little more complicated when you go to plurals and singulars. So you would have [FOREIGN]. The question was in the second study, would Spanish overhears be able to pick up this distinction and realize that something like [FOREIGN], was an error. Now notice that in English, we do have number, right? So English speakers do use, the number distinction right car versus cars. It's marked but it has an ending that tells you exactly whether it's plural or singular. I know that there are some irregularities in Spanish. There is child and children but we do have there is this s marking or that marks the plural in, in English. So that the idea was that the Spanish over heres would have learned this marking from, from English and they could then transfer that information to Spanish. So when they learned [FOREIGN] or [FOREIGN] that wouldn't be so hard for an English speaker because they do have this idea that an s marks plural. Right and the lack of an s marks singular. So, what they found was that the Spanish over hears could detect errors like [FOREIGN], but they were much less accurate in detecting errors like [FOREIGN]. And the interesting part about this is it suggests that, yes, hearing a language early in life does help people develop a better accent. But it doesn't necessarily guarantee that they will learn things like grammatical gender. Right? Which is in Spanish. Or plural markings, right? That those come later in life. And they're built upon this auditory footprint. But there's no guarantee that if that's heard young, at a young age that those things will get built up. So, in this particular case there was no advantage in this grammatical gender marking. Even when it was quite transparent like it is here, [FOREIGN] right is pretty transparent for a Spanish speaker and generally when I say those types of things to the native Spanish speakers, they feel like it's like chalk, you know, on a chalk board, it feels like nails on a chalk board. I don't find it quite as offensive, because I'm softened from English. But in any case, the overhears felt like it wasn't a problem at all.