Here's a breakdown:
* Single Sound: Even though you hear two parts, a diphthong is considered one sound. Think of it as a blend of two sounds, not two separate sounds.
* Glide: Your tongue and mouth position changes smoothly as you make the sound, moving from one vowel position to another.
* Common Examples:
* "oi" in "boy" - You start with the "o" sound and glide into the "i" sound.
* "ow" in "cow" - You start with the "o" sound and glide into the "u" sound (like in "put").
* "ay" in "say" - You start with the "a" sound and glide into the "i" sound.
Key Characteristics:
* Movement: The tongue and mouth position changes during the sound.
* Duration: Diphthongs are typically longer than single vowels.
* Stress: The first part of the diphthong is usually more prominent.
Important Note: Diphthongs can vary depending on the language and dialect.