Britannica
Sources used in this answer
How are diphthongs different from monophthongs?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
phonetics
Diagram depicting the location of human vocal organs and possible places of articulation used for speech.
In phonetics, the primary distinction between diphthongs and monophthongs lies in the stability of the vocal tract during articulation.12
- Monophthongs are often referred to as "pure" or "steady-state" vowels. Throughout their duration, they maintain a single, constant articulatory position.123
- Diphthongs are "gliding" vowels. During their production, there is a continuous transition from one articulatory position to another.142
Although both are considered single speech sounds, they are represented differently in phonetic transcription. While a monophthong is represented by a single character, a diphthong is typically denoted by a pair of characters that indicate the initial and final configurations of the vocal tract. Common examples of diphthongs in English include the vowel sounds found in words like "out" and "ice".12