When English is spoken, the speaker alternates between stressed and unstressed syllables in regular intervals, with the stresses falling within content words. This is called the Rhythm Rule. The stressed syllables of the sentence create beats. The beats of the following sentence fall on the words 'bought,' 'car,' and the first syllable of 'Tuesday.'

(What are content words and function words?)

A speaker can stress a word in any combination of the following three ways:

1. by slightly changing the pitch of the stressed syllable of the stressed word compared to the syllables around it
2. by saying the stressed syllable of that word for a longer period than normal
3. by saying the stressed syllable of that word louder than the surrounding syllables

Notice two things about the pattern of stressed and unstressed syllables in the following sentences:

1. The stressed syllables occur on regular, evenly-spaced beats, even if there is more than one unstressed syllable between stressed syllables
2. The regular stressed syllables (according to the dictionary) of the content words are the only stressed syllables of each sentence.

In addition to stressing content words, function words are often reduced in spoken English. This allows greater contrast between stressed and unstressed words.

The Rhythm Rule is more of a guideline than a rule because it is often not followed exactly. The main idea is that stresses in spoken English happen in regular intervals, or beats. The stressed syllables create the beats.

To sum up: Native English speakers generally alternate between stressed and unstressed syllables. According to the Rhythm Rule, stressed syllables usually occur at regular intervals. Non-native English speaker and ESL/ELL students can improve the perception of fluency by learning to adopt the rhythm of spoken English.