In stressed syllables, there are patterns for how vowel sounds are represented. When you are not sure what vowel is in word, the best method is to use a dictionary which uses IPA symbols to represent the vowels. Try these recommended online dictionaries:
In the stressed syllable of a word, if there is only one vowel letter (a, e, i, o, u), the vowel sound is usually the sound listed in the chart below.
For more help with American vowels, check out our Vowels Playlist on our Videos page.