What is the term for a vowel sound that contains two components, the onglide and offglide, as in 'play'?

• A. Diphthong
• B. Cuisenaire Rods
• C. Stress Pattern
• D. ESOL

Answer: (A)

Diphthongs are vowel sounds that move from one quality to another within the same syllable, using an onglide at the start and an offglide as the sound finishes. In the word "play," the vowel is a diphthong because the tongue glides from the starting vowel toward a second vowel sound as you pronounce it, producing that single, evolving vowel sound. This contrasts with pure vowels, which keep the tongue position steady throughout the vowel.

The other terms listed aren’t about vowel sounds: one is a math manipulative, another refers to where the syllable is stressed, and the last is an acronym for English language learners. So the correct term for a vowel sound with two components is diphthong.