In Dialects^x, Approximants^x

Hi, The English /v/ is a voiced labiodental fricative. I find it difficult to distinguish between this sound and the voiced labiodental approximant /ʋ/, which is found in some other languages and as an alternative to /ɹ/ in some English dialects. How does one make this distinction? Is there any...

Yes, I do sound a little like John Wayne, pardner. No need to get in a twist, King-- my tongue is obviously doing something back there: it is all tensed up, controlling the air flow and who knows what-all. The discussion, however, is intended to get foreign students to differentiate their /r/...