Sentence stress is one component of conversational speech that is often overlooked. As an important driver of the English language rhythm, it is a bigger picture concept that needs mastering to
Let me give you an example.
1) Darrel hates big dogs
2) Darrel hates big dogs
Although the 2 sentences share the same words, the emphasis difference is on "big" vs. "dogs". The first sentence suggests Darrel may have an issue with big dogs but may not have an issue with small dogs. The second sentence stresses Darrel's dislike for big dogs but maybe not big horses or big cats.
Although these are more subtle nuanced parts of English, they are an efficient way we communicate to narrow down sentence meaning.
Check out my worksheet here for more details and practice changing the stressed word in the practice sentences. Developing your ability to change the stressed word in a sentence will help you feel more comfortable doing this spontaneously.