Letter on position 1 (m) changed: 10 words basts casts easts fasts gasts lasts oasts pasts vasts wasts Letter on position 2 (a) changed: 3 words mists mosts musts Letter on position 3 (s) changed: 4 words malts marts matts mauts Letter on position 4 (t) changed: 4 words masas mases masks masus Letter on position 5 (s) changed: 1 word masty