The spelling of the word "tufnell" can be explained using the International Phonetic Alphabet (IPA). The first sound is /t/, which is a voiceless alveolar stop. The second sound is /ʌ/, which is an open-mid back unrounded vowel. The third sound is /fn/, which is a cluster of a voiceless labiodental fricative followed by a voiced alveolar nasal. The last sound is /l/, which is a voiced alveolar lateral approximant. Therefore, the correct spelling of this word is "tufnell," not "tuffnel" or "tufnel."