Diphthong is an odd word. It means two distinct vowel sounds together. A lot of vowel combinations – like ‘means’ in the previous sentence, or the ‘ou’ of ‘previous’ in this one – are just one sound without the mouth changing shape. Some, though, need you to enunciate the change quite markedly.

I don’t think the wikipedia entry above is particularly good, but I give it anyway for background. For me a good example of a diphthong is where you hear Liam Gallagher pronounce words like ‘imaginasheeun‘ on the rather stupendous Cigarettes and Alcohol.

Regardless of how you define or exemplify a diphthong, I think it’s more than a touch ironic that the word diphthong itself has four consonants in a row. Four consonants together, you don’t see that very often. Rather like the word naphthalene that I remember from my school physics days.

Perhaps I should get out more…