The spelling of the phrase "most third string" follows the rules of English phonetics. "Most" is pronounced /moʊst/, with the "o" sounding like the "o" in "go" and the "st" ending pronounced as a voiceless consonant. "Third" is pronounced /θɜrd/, with the "th" sound as in "thin" and the "r" sound at the end. "String" is pronounced /strɪŋ/, with the "i" sounding like the "i" in "bit" and the "ng" ending pronounced as a single sound. Thus, the spelling of the word reflects the sounds of each individual letter.