Hmm I just thought I'd mention here that as a native speaker I couldn't pronounce the TH, eg in 'three' or 'thumb' until I was about 13, I could pronounce th in 'the' though.
One of my teachers at school noticed one day and made me have speech lessons, it took a couple of months to get it fixed!
>> In America, we always pronounce the "th" at the end. However, there are some people who do not, most noteably, the blacks (they say "fif and sixf). <<<
I've heard several African-Americans pronounce Aretha (Franklin) as "Aree-Fuh" and Luther (Vandross) as "Lu-Fuh." They also tend not to pronounce the "g" in stength so that it comes out as "strenth." Another common mispronounciation among this culture is "aks" instead of "ask" -- and this from many prominent, educated African-Americans so I wonder if this is done deliberately to emphasize their "blackness" or to give themselves some "street cred."
in facet, after reading your post I realize that I don't pronounce the 'g' in 'strenght'. I'm not African-Americans, though. It's almost impossible to pronounce it. How can I do ?
> "aks" instead of "ask"
That is indeed common, and sounds TERRIBLE, but it isn't limited to African Americans.