The spelling of the word "quelched" is derived from its pronunciation, which is represented in IPA phonetic transcription as /kwɛltʃt/. The first syllable is pronounced with the "k" and "w" sounds, followed by a short "e" sound and a "l" sound. The second syllable features a "tʃ" sound, which represents the "ch" sound in "cheese". The spelling of the word may be confusing, but understanding its pronunciation can help make it easier to remember and use correctly.