What is a diphthong? Diphthongs are considered single phonemes, each having a sequence of two different vowel positions. One of the positions is the dominant nucleus (sometimes called the radical) with greater duration; the other position, the glide (or vanish), is of reduced duration and stress. Both positions are taken in a single syllable. All diphthong phonemes of American-English move from the nucleus to the glide position.
The children I have been working with all seem to have difficulty with the glide part of the diphthong. My experience has been that they are capable of producing the nucleus….however delete the glide completely. When given a verbal and visual cue…and when just producing the diphthong in isolation….they are capable of producing both the nucleus and the glide. However….once in a word….the glide is deleted.
To improve your little one’s ability….it is best to start off with words that are consonant-vowel words (and do NOT have a consonant that follows the vowel). An example of this would be the following…..best to start off with words like: BYE……..and work towards words like: BIKE. Both of these words start off with the consonant B…..followed by the same diphthong…however, in the word: BIKE…..the consonant K ends the word….making it a little more challenging.