Word Stress and Vowel Reduction
Word stress is closely related to vowel reduction. Vowel reduction is another important feature of oral English. What does it mean? It means that a vowel sound is pronounced [ə] or [ɪ] instead of another full vowel. For example, the letter <a> in the word about is not pronounced [ɑ] that is present in the word father. This would result to the incorrect form *[ɑbaʊt]. Instead, this vowel sound is reduced to [ə], yielding to the correct pronunciation [ əˈbaʊt].
Vowel reduction is a very common phenomenon in English. If you browse through a dictionary, you will notice that a lot of unstressed syllables have [ə] or [ɪ] as their vowel sound. If you pay attention to the pronunciation of learners of English, you will also notice that very often those vowels which should be reduced are not, and the speakers will produce a full vowel sound.
Exercise 1: Browse through a dictionary of English which shows the pronunciation of the words. Find 10 words that present a vowel reduction for which you might have mistakenly expected that they would be pronounced with a full vowel. Indicate which vowels are reduced. Then, read those words aloud to a partner and make sure that you reduce the appropriate vowels.
Exercise 2: In your daily life, pay attention to the pronunciation of the words you hear and write down ten words that have a vowel reduction. Indicate which vowels are reduced. If you do not live in an environment where you can interact with English speakers, you can always listen to something in English on TV, on the radio, or on the internet.