The spelling of the word "under selfish" is straightforward using the International Phonetic Alphabet (IPA) transcription system. "Under" is pronounced /ˈʌndər/ with a short "u" sound, "n" sound, schwa sound, "d" sound, and reduced "r" sound. "Selfish" is pronounced /ˈsɛlfɪʃ/ with a stress on the first syllable, "s" sound, "ɛ" sound, "l" sound, "f" sound, "ɪ" sound, and "ʃ" sound. The proper use of IPA helps learners to accurately pronounce words and improve their English pronunciation.