> A Japanese speaker won't be able to tell that they're saying [r] in an English word that has an /l/.
There's an interesting phenomenon here. As previously mentioned, my mind has partially assimilated to losing the s/sh distinction. I had a chinese tutor who merged those two sounds, and it stopped bothering me. The same tutor also merged n/l and r/y. I didn't assimilate to those; hearing n where the word I knew used l confused me every single time.
What's relevant is that she didn't merge n/l in her english (which was not fluent). That suggests to me that she might have been able retrospectively to identify which she had just used for a mandarin word like 能 (neng). I agree that that depends on having been trained to recognize the distinction, although I find it slightly odd that she wasn't trained to make it in Mandarin. But, grand summary, I suspect a Japanese speaker could be trained to recognize the distinction even in Japanese.
More generally, I don't think the phenomenon of not distinguishing two different sounds (your Japanese speaker) is the same as the phenomenon of fantasizing that you're distinguishing two identical sounds (your english speaker).
> The same way that you perceive "a" and "A" to be the same grapheme despite seeing different shapes, Japanese speakers consider [r] and [l] to be the same phoneme /R/ despite hearing different sounds.
I know that "a" and "A" are the same letter, but I'm easily capable of distinguishing them on demand. In fact, I'm likely to get upset when one is used where I think the other should be. I don't think that mirrors the r/l situation in Japanese. Similarly, I don't vary freely between A and a (and, owing to personal aesthetics, never write α unless I have to write cursive); I follow a fairly clear set of rules that determines one or the other. I know that situation does not reflect the r/l situation in Japanese, although I don't know that it doesn't reflect the situation of any given speaker.
Given a hypothetical Japanese speaker who's capable of producing r and l allophones, if you asked them to repeat a sentence including "are" realized as "ale", down to mimicking the accent, how likely do you think they would be to mimic that realization of [l]?
Of course it is possible, but it is quite difficult. It is easier for children, and generally gets harder with age.
But it also holds true that it gets easier to learn new languages, if you do it a lot. I've heard a lot of people say that it gets easier after the fifth language. I'm only up to four (Norwegian, English, Japanese and French - with a basic understanding of other European "dialects" - German, Spanish, Italian -- and of course "Scandinavian dialects" of Swedish and Danish) -- and I can imagine that if I learned one more "truly distinctive" language, like Finnish, or Mandarin -- I'd start to know more of the "possible ways" we use sounds -- and it would therefore be easier to choose "the right subset" for a new language.
In addition to mimicking accents, singing can be a very useful way to train pronunciation.
There's an interesting phenomenon here. As previously mentioned, my mind has partially assimilated to losing the s/sh distinction. I had a chinese tutor who merged those two sounds, and it stopped bothering me. The same tutor also merged n/l and r/y. I didn't assimilate to those; hearing n where the word I knew used l confused me every single time.
What's relevant is that she didn't merge n/l in her english (which was not fluent). That suggests to me that she might have been able retrospectively to identify which she had just used for a mandarin word like 能 (neng). I agree that that depends on having been trained to recognize the distinction, although I find it slightly odd that she wasn't trained to make it in Mandarin. But, grand summary, I suspect a Japanese speaker could be trained to recognize the distinction even in Japanese.
More generally, I don't think the phenomenon of not distinguishing two different sounds (your Japanese speaker) is the same as the phenomenon of fantasizing that you're distinguishing two identical sounds (your english speaker).
> The same way that you perceive "a" and "A" to be the same grapheme despite seeing different shapes, Japanese speakers consider [r] and [l] to be the same phoneme /R/ despite hearing different sounds.
I know that "a" and "A" are the same letter, but I'm easily capable of distinguishing them on demand. In fact, I'm likely to get upset when one is used where I think the other should be. I don't think that mirrors the r/l situation in Japanese. Similarly, I don't vary freely between A and a (and, owing to personal aesthetics, never write α unless I have to write cursive); I follow a fairly clear set of rules that determines one or the other. I know that situation does not reflect the r/l situation in Japanese, although I don't know that it doesn't reflect the situation of any given speaker.
Given a hypothetical Japanese speaker who's capable of producing r and l allophones, if you asked them to repeat a sentence including "are" realized as "ale", down to mimicking the accent, how likely do you think they would be to mimic that realization of [l]?