Letter on position 1 (b) changed: 12 words aids cids fids gids kids lids mids nids rids tids vids yids Letter on position 2 (i) changed: 4 words bads beds bods buds Letter on position 3 (d) changed: 6 words bias bibs bigs bins bios bits Letter on position 4 (s) changed: 2 words bide bidi