For decades, Gruber observed that one of the biggest hurdles for English learners wasn't just vocabulary, but the "music" of the language—. He realized that when speakers place emphasis on the wrong part of a word (like saying "pho-TO-graph-er" instead of "pho-TOG-ra-pher"), listeners often struggle to understand them, regardless of how "fluent" they seem.
Here are some common patterns of syllable stress in English: The Syllable Stress Survival Guide Pdf