More or less prominent words and syllables are generally said to have more or less stress. Crucially, stress isn’t simply an yes-or-no proposition: words can have a lot of stress, a little bit, or none at all.
Words of more than one syllable, of course, have both stressed and unstressed syllables.
pumpkin
basket
pretend
Words of three or more syllables usually have three levels of stress (I’ve used bold for primary stress and underlining for secondary stress):
telephone
secretary
educational
This is called lexical stress, or word stress. It is part of the basic structure of words in English—it is marked in dictionary entries, and is basically invariable for given words. It’s essential to get right, of course, and needs to be learned whenever you are learning new words.
sentence stress
There’s another kind of stress, though—what is often called sentence stress. In connected speech, we don’t put equal emphasis on all stressed syllables. Take the sentence:
Many of the penguin’s friends became disoriented.
Not all of these words will receive equal stress. Of and the are function words—little bits of grammar—and rarely receive any stress in connected speech. Became is a content word, but it’s unlikely to receive much stress here, as the other words in the sentence carry the main information. The lexically-stressed syllables of all the other words—many, penguin, friends, and disoriented—are likely to receive at least some stress:
Many of the penguin’s friends became disoriented.
…you should be able to hear that the syllables ma- (in many), peng- (in penguin), friends, and -or- (in disoriented) are more strongly stressed—more prominent—than the other syllables in the sentence. They have sentence stress. You may also be able to hear that the stressed syllable in disoriented sounds the most prominent of all. (If you can’t yet, don’t worry about it. Going through these pages will help you to continue to tune your ear for prominence in English.)
While lexical stress is invariable, sentence stress is flexible. Here is another way to say the same sentence:
Many of the penguin’s friends became disoriented.
Here many and penguin’s have largely lost any real prominence—they no longer have sentence stress. We’ve gone from four strong stresses down to two.
So what is stress?
Stress, in English, is a function of four things:
Duration
Loudness
Vowel quality
Pitch
Stressed syllables last longer than unstressed syllables (duration). They have a little bit more vocal energy in them, which we hear as loudness. The vowel quality itself can change—becoming more strongly defined, in the case of strongly stressed syllables, and “reducing” towards a schwa, in the case of many unstressed syllables. And finally, the pitch of the voice can raise or lower on stressed syllables, lending prominence. All of these cues are important signals to prominence, and important for non-native speakers to master. As far as intonation is concerned, though, the most important are the first and the last: duration and pitch.
As we go through the many examples on the following pages, keep an eye and an ear out for duration—for how much longer prominent syllables tend to be. I will continue to refer back to it and point it out from time to time. (Duration is also an important cue to boundaries, as well as to prominence.)
But now we will turn our focus mainly to what is probably the most important of these four, the aspect of intonation that contributes the most to meaning: pitch.