To express "500 euros" in English, you would state it as "five hundred euros." It is important to note that "euro" is indeed a plural noun in English, thus it should not be followed by an article or shown as singular. The incorrect mention of "兄升肆" does not align with the topic at hand, and it seems to be a separate and unintelligible statement. The sentence structure should be revised to maintain clarity and coherence, ensuring that the topic of discussing the translation of euros is maintained throughout the text.