One thing I love about teaching ESL is that I learn many things about the English language that I never knew before--things like pronunciation of English words and grammar structures that I never had to consciously think about before I began teaching ESL because I had intuitively picked these things up as a child during my first language acquisition years.
For example, I am signed up for dictionary.com's "Word of the Day." Today's word is "factitious." Yesterday's was "abominate," and the word from February 11th was "ersatz." Do you know how to pronounce these words? Specifically, where is the syllable stress for each word? If you pronounce these words "fak-TISH-uhs," "uh-BOM-uh-nayt," and "AIR-sahts" (or "UR-sats"), you are correct! So if you were correct, HOW did you know that? If you're like me, you probably just had an intuitive sense for it. But let's say you were teaching a non-native English speaker new vocabulary and they asked you how to pronounce the word. What would you tell them? You’d likely pronounce the word for them. But could you tell them why you pronounce it that way?
As a native speaker of English, I take for granted the fact that I know intuitively how to pronounce English words with relative ease. Non-native English speakers who are learning new vocabulary words for the first time, however, have to learn both segmental pronunciation (the individual sounds of a word) and suprasegmental pronunciation (syllable stress, word stress, rhythm, intonation, etc.). When I come across a particularly challenging unfamiliar word not stored in my present lexicon, however, I experience something similar to what ESOL students experience when they come across unfamiliar words in their reading: I have to consciously think about how to pronounce the word. I'm usually pretty good at sounding out the word (segmental pronunciation), but the syllable stress (suprasegmental pronunciation) can be tricky. Of course, being a native speaker of English, I can usually intuitively figure it out without much thought. But what about our non-native English speakers? Are there any rules we can use to help them?
Unfortunately, English doesn't have many hard and fast rules for suprasegmental pronunciation like it does for segmental pronunciation (i.e., phonics rules). There are, however, some guidelines that can be used to help predict word stress.