[edzillion]

There is also another interesting unwritten rule of the English language at play here. The rule goes like this:

In a series of words which differ only (or mostly) by the vowel used, the order should be e, i, a, o

- tic tac toe

- flim flam

- ding dong

- king kong

If you doubt it, try saying the opposite and hear how odd it sounds: The clock went 'Tock Tick'

[Anon4Now]

Bingo bango bongo, I never noticed that. I tried saying 'fee fi fo fum' backwards and it took me about 10 times to get it right. There's almost a musical cadence to the usual order that just sounds off key when said backwards.

[rippercushions]

This is language-dependent. The Japanese syllabary is sorted in the order a-i-u-e-o, which is weird to the Western ear, but as ubiquitous as A-B-C in Japan.

[doomrobo]

Yup! It's called ablaut. English has ablaut reduplication for children's words like kitty-cat or sing-song

[jihadjihad]

It's probably not unwritten. It's similar to how we conjugate irregular verbs like "sing/ring" or "beget". The topic in linguistics is called vowel gradation [0].

0: https://en.m.wikipedia.org/wiki/Apophony

[SoftTalker]

Bada bing a counter example?

[JustLurking2022]

Not really, unlike the other examples the words differ by more than just the vowel sound.

[russdill]

I think the a sound in ba and da just isn't included in the list.