not've

not +‎ -'ve

• (US) IPA^(key): /ˈnɑtəv/
• (Received Pronunciation) IPA^(key): /ˈnɒtəv/

not've

1. Contraction of not have.
   • 1998, David Weber, The War God's Own, →ISBN:

     I'd not've fallen in if you'd've told me it was there, Da. And I'd not've sunk if you'd've taught me how to swim.

   • 2005, George Singleton, Novel:

     Mac McAdams might not've added all those "ayes," but he spoke in such a melodious dialect that "aye" kind of came out understood.

   • 2018, MST3K, Turkey Day, and 30 years of taking over the world before pie is served‎:

     “To the fan, did it add that much value?” Nelson wondered. “Was it worth that much time? I don’t know. It might not’ve.”

• Vento