I recently composed music for a poem which contains the word single. When I was typing the words in the music notation file, I was momentarily flummoxed by where to divide the word (indicated with a hyphen in music notation). sin-gle didn’t look right, but sing-le looked totally wrong (as it’s not related to ‘sing’). Various websites suggested sin-gle, but Google’s AI Overview told me “No, you should not hyphenate the word “single” because it is a one-syllable word.” Huh?
A syllable is built around a nucleus, which is most often a vowel, but in English can be a small number of consonants, l, r, m, n or ŋ (ng). Other languages allow more (see the Wikipedia article.) The nucleus of the second syllable of single is l. Or maybe it’s ə for some people.
There are two complications. The first is that we pronounce single as sɪŋ g(ə)l, which should be spelled sing-gle, which looks totally wrong. The second is that we sing vowels for as long as possible, and either place the consonant on the beginning of the next syllable (especially if it starts with a vowel), or as late as possible (especially if the next syllable starts with a consonant. (One score one choir I sing in found on the internet took this to its logical extreme and had words like e-xce-lsis and a-gnus, which were very distracting.)
The same poem contains the word nightingale, which similarly is night-in-gale. gale is clearly a separate syllable, but the same two complications apply.
I thought I remembered another song using single, but it’s actually simple, to which most of the same issues apply.
PS Language Log has a series of posts on AI’s inability to count the number of times a certain letter appears in a word or word in a text, starting here.