“Commonest mistakes” - ftfy I concur with GP. IME, “most common” or “most fun” is generally looked upon as better form than “commonest”, or “funnest”. The latt

“Commonest mistakes” - ftfy I concur with GP. IME, “most common” or “most fun” is generally looked upon as better form than “commonest”, or “funnest”. The latter catches the eye and not in a good way, having as it does the ring of childishness to it. Legal, sure. Proper? Nope.