In many Slavic languages there's a concept of "soft" and "hard" consonants. In Russian and Ukrainian, for example, whether the consonant is of either kind is determined by either the vowel that follows it or a special other letter, or, in case of Ukrainian, an apostrophe. In Polish, there's a diacritic sign for the same purpose, which is for some reason reversed for L.

Anyways. The example that is very tricky to get right for an English speaker in Russian is:

    * мат (carpet)
    * мать (mother)
    * мять (crumple)
    * мят (crumpled)

All four words usually sound the same to an English speaker. It's usually easier to tell the first two from the last two.

I’m not American, but I after living here - I’ve noticed a few. They sometimes say “axe” for “ask”. They fail to enunciate “respiratory” fully - they say “res-pah-tory”. Also, they fail to pronounce the f in fifth - like they say fith. Certain words like “squirrel” tend to get squished into “skwol” while I’m used to pronouncing it in two syllables. I’m trying to think of similar examples.

Edit : I now realise that all of the above are incorrect examples in the context of what is being discussed. Pardon me!

Oh, and in Hebrew, while it's not acknowledged by the speakers themselves, there's also two different ways to pronounce "L" ("lamed"), while English speakers only utilize one of the two ways. So, they manage to say "lomed" (לומד, studies) more or less correctly, but "lo" (לא, no) sounds funny to a native speaker, because the "L" is supposed to be "soft".

Native English speakers when trying to speak Portuguese find it hard to speak A with tilde (~). Like when they say "São Paulo" they say "Sao Paulo". Ã is the nasal A, which sounds like the U in "sun" and "burn", while the standard A sounds the same as in "car".

I don't know why this happens, since the phoneme exists in English...