Historical clue formulations

• Double-apostrophe contraction — 2019-06-18
• Word with two apostrophes — 2016-03-27
• Contraction with two apostrophes — 2011-08-14
• "If only ___ known ..." — 2009-10-04
• Double contraction — 2005-03-09
• "If I Knew You Were Comin' ___ Baked a Cake" — 1997-02-12