Some interjections are completely inscrutable without translation. The Chinese "哎呀", pronounced [aija] in IPA or "aiya" in pinyin which can take different tones, is uttered for a big surprise. Conversely, English "Uh-huh" ("yes") or "Uh-uh" ("no") is completely unintelligible to a Chinese with no knowledge of English.[note] This fact may not be immediately appreciated by the speaker, causing confusion in a conversation. There's no problem if I say "uh-huh" to a Chinese having lived in the US for some time, in an all-Chinese conversation. I may be lightly laughed at but well understood if I say it to a Chinese that has learned English for some time. But if I say it to my parents who know no English at all, they assume I didn't catch the part of the conversation right before this point.
Thus, we see that interjections, unlike words of other classes, are special in that the speaker unconsciously uses one unique to a specific language in the environment this language is spoken, even when he converses in another language, often his mother tongue. It is not conspicuous to his mind that interjections may be just as language-specific as are other types of words.
[note] These yes-no words may not be considered by some as interjections.