Not exactly a shortening, per se. "oft-", not "oft", is the prefix[0] form of "often". I'd guess "oft" on it's own would probably be archaic. [0] https://en.w

Not exactly a shortening, per se. "oft-", not "oft", is the prefix[0] form of "often". I'd guess "oft" on it's own would probably be archaic. [0] https://en.wiktionary.org/wiki/oft- https://en.wiktionary.org/wiki/oft-