The correct spelling of the phrase "more fastening" can be explained using the International Phonetic Alphabet (IPA) as /mɔr ˈfæstənɪŋ/. The IPA symbols represent the sounds of each letter and combination of letters in the word. "More" is pronounced with the open-mid back rounded vowel /ɔr/, while "fastening" is pronounced with a short A sound /æ/ followed by the consonant cluster /st/ and ending with the suffix /-ɪŋ/. Proper spelling ensures clear communication and better understanding in written language.