Patterns of Sound Change Notes

General Mechanisms: Regularity and systematicity in sound changes; identifying exceptions and individual phoneme changes.

The phrase "across the board or not" refers to whether a sound change applies universally across all instances of a particular phoneme or is restricted to specific environments or contexts.

Why are there exceptions?: Exceptions exist due to various factors, such as historical usage, influence from other languages, or specific phonetic environments that can alter how a sound change is applied. These factors contribute to language complexity and can result in inconsistencies in sound changes across different dialects or varieties of a language.