Linguistics
Why 'trust' is a possible English word and 'rtsut' could never be
Linguists rank speech sounds on a sonority scale, from quiet stops to loud vowels, and most languages build syllables by climbing to a peak and falling back down. In 'trust', the onset rises t-to-r toward the vowel and the coda falls u-to-s-to-t away from it — the Sonority Sequencing Principle. Break that rise-then-fall order and a string of sounds stops feeling like a possible word at all.