benefitted

Usage notes

 * Of English verbs with stems ending in -fit, only those derived from have the standard present participle and past spelled with double "t". Verbs otherwise derived, like, , and  have present participle and past spelled with a single "t". More than 10% of the occurrences of some of these forms are spelled with a double "tt" in edited works in the US, fewer in the UK. Most dictionaries do not recognize the double-"t" spelling, despite its persistence for at least 200 years in the US.