What does the term vowel diphthong refer to?

The term vowel diphthong refers to the blending of two vowel sounds, which is why the chosen answer is correct. In linguistics, a diphthong occurs when two vowel sounds are pronounced together within the same syllable, leading to a smooth transition from the first vowel sound to the second. This creates a unique sound that is distinct from either vowel alone.

For example, the diphthong in the word "coin" begins with an "o" sound and glides into a short "i" sound. This blending aspect is crucial to defining what a diphthong is and differentiates it from other vowel sounds.

Understanding diphthongs is important for various aspects of language arts, including phonics and pronunciation, as they play a significant role in how words are spoken and heard.