Editing Openai/69186d20-2d14-8013-b9c6-c09000f173f6 (section)

==== For each consonant, do this: ====
# Group vowels into known digraphs: - ae, ao, eo, ia, io, oi, ui, ua, ea, ai (etc.) - These count as one vowel unit for “how many vowel sounds per syllable”. - But each component letter still has a class: - broad: a/o/u - slender: e/i
# For that consonant, look for the closest vowel letter (or digraph component) on each side within its syllable/morpheme. - Left side: walk left until you hit a vowel or a boundary. - Right side: walk right until you hit a vowel or a boundary.
# If nearest on one side is clearly closer, use that side to decide: - nearest left is one letter away (a), nearest right is three letters away (i) → broad.
# If both nearest vowels are equally close but same class (both broad or both slender) → easy. - consonant is that class.
# If both nearest vowels are equally close but different classes (true “mixed case”): - Ask: which side does the consonant really belong to syllable-wise / morpheme-wise? - That side wins. In practice this shows up in relatively few words and is often lexicalized: you just learn that consonant as broad or slender.

The key: once you respect digraph grouping and syllable/morpheme boundaries, almost everything beginners see stops being ambiguous.