The spelling of the word "ass sling" can be explained using the International Phonetic Alphabet (IPA). The IPA symbols for this word are /æs slɪŋ/. The symbol /æ/ represents the short "a" sound in "ass", while /s/ and /l/ represent the sounds of these letters in English. The symbol /ɪ/ represents the short "i" sound in "sling", and /ŋ/ represents the final "ng" sound. While the word may be considered vulgar, understanding its phonetic transcription can help to accurately spell and pronounce it.