English Pronunciation

Introduction to American English Semi-vowels

Diagram of English semi-vowels sounds for ESL students and teachers

What makes a sound a semi-vowel?

The w sound and y sound are the only two semi-vowels (also commonly called glides) in English. These sounds can be created with slightly greater restriction in the vocal tract than vowels, but less restriction than most other consonants.

The w sound and y sound are known as "semi-vowels" for many good reasons. Because the letters w and y can be used to spell vowel sounds and because the w sound and y sound are each a portion of two-sound vowels, they are sometimes thought of as vowel sounds. However, the w sound and y sound are not vowel sounds because they cannot be syllabic (they cannot create a syllable). For example, if the w sound and y sound could create a syllable, the words when, we, you, and year (among many others) would be pronounced with two syllables.

Additional confusion is created because both the w sound and y sound can combine with vowels to create two-sound vowels. These cases are separate from the use of w and y as representatives of distinct vowel sounds, however.

Vowel Sounds spelled with w and y

Generally speaking, the letters w and y will represent a w sound or y sound when they are:

  • at the beginning of a word (will, you)
  • the first letter of part of a compound word (homework, backyard)
  • the first letter after a prefix (rewind, beyond )

Additionally, the letter w usually represents a consonant sound when it follows another consonant, such as in the word sweet.

In other positions within a word, the letters w and y are usually associated with the spelling of a vowel sound. When the letters w and y are used in vowel spellings, they are representing the vowel sound, and not a w sound or y sound.

Vowel sounds spelled with a w
spelling sound example
awaw soundsaw
ewoo soundnew
ewlong ufew
owlong osnow
owow soundcow
Vowel sounds spelled with a y
spelling sound example
ylong ehappy
ylong iby
yshort imystic
oyoi soundtoy
aylong aday

Review of two-sound vowels

A two-sound vowel is a vowel sound that includes a w sound or a y sound in the pronunciation. Often, the w sound or y sound is only a minor part of the sound, but must be included for the sound to be pronounced fully. Two-sound vowels are known linguistically as diphthongs, pronounced dip-thong or dif-thong.

In NAE, the long a, long i, long o, long u, ow sound and oi sound are two-sound vowels.

Linking vowels with semi-vowels

A slight w sound or y sound may be added into or between words when there would otherwise be two adjacent vowel sounds. The addition of the semi-vowel sound helps the speaker clearly articulate both vowel sounds. If the first vowel is a two-sound vowel that already ends in a slight w sound or y sound, the semi-vowel will be made more significant. Although native speakers regularly and naturally add these sounds to their speech, dictionaries do not include the added sound in their transcriptions.

Adding a w sound Between Vowels
within wordsbetween words
herowic who_w_asked
intuwition go_w_away
fluwent do_w_it
Adding a y sound Between Vowels
within wordsbetween words
ideya say_y_it
reyact day_y_after
sciyence dry_y_off

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w sound in qu spelling

y sound, w sound high frequency

Sound Practice

glide w

glide y

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