This document provides an introduction to English vowels, including:
1) The three basic dimensions of vowels are height, advancement, and rounding. Vowels can be high, mid, or low in height; front, central, or back in advancement; and rounded or unrounded.
2) The key vowels of English are [i a u], known as the point vowels.
3) Traditional vowel diagrams use the first and second formants (F1 and F2) to represent vowel quality, which correlates well with physical tongue position differences.