The document discusses sentence stress in English. The main points are:
1. Sentence stress refers to emphasizing certain words within a sentence, giving the sentence rhythm.
2. Words in a sentence can be classified as either content words, which carry the main meaning, or structure words, which are less important grammatically. Content words receive stress while structure words are unstressed.
3. The time between stressed content words should remain constant to maintain the rhythm of English speech. Structure words can be said more quickly or slowly to achieve this constant rhythm.