The spelling of the word "KEIS" can be explained using the International Phonetic Alphabet (IPA) phonetic transcription. The first sound in "KEIS" is a voiceless velar fricative, represented in the IPA as /k/. The second sound is a close front unrounded vowel, represented as /i/. The final sound is another voiceless fricative, this time a voiceless alveolar sibilant, represented as /s/. Therefore, "KEIS" is spelled as it is pronounced, using the sounds /k/ + /i/ + /s/.