1. Syllable: The most common interpretation is that the "part" of a stressed word refers to the stressed syllable. Every word in English has at least one stressed syllable. When we say a word, we emphasize that syllable, making it louder and longer.
Example: "REcord" - the first syllable is stressed. "PreSENT" - the second syllable is stressed.
2. Sound: Another interpretation is that the "part" refers to the sound that is stressed in a word. This is often used in phonetics to indicate which sound is emphasized.
Example: "back" - the initial "b" sound is stressed. "record" - the "c" sound is stressed.
3. Emphasis: You might be asking about the emphasis placed on certain words in a sentence. This is related to how the meaning of a sentence can change based on which word is stressed.
Example: "I ate the apple." (Focus on the action of eating) vs. "I ate the apple." (Focus on which apple was eaten)
Can you clarify your question? For instance, are you interested in how stress affects the pronunciation of words? Or do you want to understand how stress can be used to convey different meanings in sentences?
Once you clarify your question, I can give you a more specific and accurate answer.