[kijin]

In general, sloppy pronunciation is more common in countries where most people have little to no contact with anyone who speaks a different language. In order to learn that your vowels are not the only vowels that exist, you need to encounter people who use different vowels, and this needs to start at a very young age when your brain can still pick up the difference.

I recently talked to an Asian man who couldn't hear any difference between "R" and "L", let alone pronounce them. That's what happens when you only speak and hear a single language for decades. Your brain gets wired to ignore any variation that isn't significant in your own language. My "L" really sounds like "R" to him, and your name really sounds like "Nate" to a lot of Americans.

Hopefully, the increasing influx of Spanish and Chinese speakers into the U.S. will force Americans to hear other languages more often in their daily lives.

[dllthomas]

Not just "a different language" but "the relevant language (or something close enough to have the same phonemes)".

[kijin]

Any language is better than none. It's much easier for someone who is familiar with two languages to learn the basics of a third language, than it is for someone who has only ever spoken one language to learn the basics of a second language (his first foreign language).

[dllthomas]

Possibly. I just know that learning Polish, it is being hard for me to distinguish sounds despite speaking various amounts of Spanish, Japanese, German, Hebrew, and Bahasa Indonesia at various points in my life.