The spelling of the word 'SONAS' can be explained using the International Phonetic Alphabet (IPA) transcription. The first letter 'S' is pronounced as /s/, followed by 'O', which is pronounced as /ɑː/. The third letter 'N' is pronounced as /n/ and the fourth letter 'A' is pronounced as /æ/. Lastly, the final letter 'S' is pronounced as /z/. This spelling is important to remember as it is the Gaelic word for 'happiness' or 'joy', widely used in Scotland and Ireland.