The spelling of the word "wert fault" can be explained using the International Phonetic Alphabet (IPA). "Wert" is pronounced as /wʌrt/ which indicates that it starts with a "w" sound and is followed by a short "u" sound, then "r" and "t" respectively. "Fault" is pronounced as /fɔlt/ which means it starts with an "f" sound, followed by an "o" sound, and then "l" and "t" respectively. Together, the two words create a phrase that could indicate a mistake that occurred in the past.