To communicate clearly when you are speaking in English, it's important to stress the correct syllables in each word. This is called word stress, which means pronouncing one syllable of a multisyllabic word with greater emphasis (stress) than the other syllables in the word.
Why do we have word stress?
Fluent English speakers use word stress to communicate rapidly and accurately, even in difficult conditions. If, for example, you do not hear a word clearly, you can still understand the word because of the position of the stress.
How is word stress different from stress?
Word stress is saying one syllable of a word louder and longer than the other syllables. The word “painting,” for instance, has two syllables. The stress is on the first syllable. Sentence stress is saying a word or words in a sentence louder and longer than the other words.