The spelling of the word "TONFIN" can be broken down using IPA phonetic transcription. The first syllable, "TON," is pronounced as "tɑn," with the "o" sound as in "top" and a stressed "n" ending. The second syllable, "FIN," is pronounced as "fɪn," with an "i" sound as in "sit" and a stressed "n" ending. Put together, the word is pronounced as "tɑn.fɪn." It is important to understand phonetics to correctly spell and pronounce words.