Re:That is why it is so hard for us, adult immigrantuses, to learn to speak without an accent, if it's at all possible... Excuse us.

Dear viktor,
Don't worry about it! In my family, my sister is married to a Japanese national, and her marriage name, Tsuyuki, contains a ts sound, that unless you have learned at an early age is hard to "hear" as being different from a plain S sound--so she often 'mispronounces' her own name.

her maiden name, Reilly-- gives her husband problems, and is just as like like to sound like Leary when he says it!

even those of use who speak english as a native language, sometime have trouble with D/J-- during comes out of my mouth and enters my ear as juring-- but i have asked others to listen for the word as i speak, and they all swear i am saying during--i know i am not!

others here can give many other examples...