Movement along this chart doesn't seem to necessarily correspond with movement on the one it's copying. Talk about a great vowel shift!
Have you talked about this puzzle with your friends? Hold your tongue! After going from one alphabet set to the other, you'll want to convert back before the answer becomes apparent.
Sick people sound bored when they mourn, because their noses are blocked.
In this puzzle, that would mean BOARD occupies a square the IPA would call SH (something you'll hear if you try solving this puzzle in a library).
More than one word can lie in the same square, but luckily the common English consonants and vowels hardly overlap here.