The spelling of the word "METHA" can be confusing due to its unusual pronunciation. The correct phonetic transcription is /ˈmɛθə/, with the first syllable pronounced as "meth" and the second syllable as "uh". The letter "a" in the spelling serves as a schwa sound, which is a neutral vowel sound typically found in unstressed syllables. It is important to use proper phonetic transcription to accurately represent the pronunciation of words, especially for non-native English speakers.