distinguish between ...

Sometimes I can't distinguish between the two sounds /e/ and /@/,when American people pronounce them, as in the words "enter" and "anti-"; Especially when the sound /e/ is a little more stretched for further emphasis. Can anybody help me with this?

Practice and more practice. Many foreigners I know have trouble distinguishing them but this rarely affects comprehension. The context alone should make up for this confusion.

<<Sometimes I can't distinguish between the two sounds /e/ and /@/,when American people pronounce them, as in the words "enter" and "anti-"; Especially when the sound /e/ is a little more stretched for further emphasis. Can anybody help me with this? >>

Well, first of all, ''anti'' does not start with a schwa sound. Also the ''e'' sound at the beginning of ''enter'' is /E/ not /e/.

Here are some articles you might want to read about the sounds that might help you be able to distinguish them:

http://en.wikipedia.org/wiki/Close_front_unrounded_vowel /{/

http://en.wikipedia.org/wiki/Open-mid_front_unrounded_vowel /E/

By /e/ in "enter" and /@/ in "anti-", I think he was referring to Antimoon's pronunciation guide.

To distinguish between those sounds in certain American dialects, you'll also have to be aware of this:

http://en.wikipedia.org/wiki/Ae_tensing

The thing is, in some dialects, @ is turned into something that sounds like e.., and the only phonetic difference between "man" and "men" is the schwa that's inserted afterwards.

man => me..n
men => men (no schwa + the vowel is noticeably shorter)