A list of contractions from divinewrite and a regex to find and eradicate the more unseemly from your documents (remember to use a case-insensitive search).
Regex to catch both the “least formal” and “less formal” contractions:
\b((could|how|might|must|should|that|what|when|where|why|would|it)n?['‘’](d|ll|re|ve)|why['‘’]s|we['‘’](d|re|ve|ll)|s?he['‘’](s|d|ll)|(where|how|when|who)['‘’](s)|(who|you|it)['‘’](d)|(they|who)['‘’](ll|ve)|(might|must)n['‘’]t|i'd)\b
Regex to catch these: