Whomever is the objective form of “whoever,” used when the person you're referring to receives an action rather than performs it. For example, in “I saw whomever you invited,” the word refers to the person who was invited, not the person doing the seeing.

The distinction between whoever and whomever trips up many adults, so it can understandably seem confusing. Here's a simple test: if you could replace the word with “him” or “her,” use whomever. If you'd use “he” or “she,” use whoever. “I saw him” works (so use whomever), but “He arrived” works (so you'd use whoever).

In practice, whomever appears most often after prepositions like “to” or “for”: “This prize goes to whoever finishes first” or “Vote for whomever you trust most.”

The word sounds formal and careful, which is why many people simply use whoever in casual conversation. You'll see whomever more often in writing than in speech. Still, knowing when to use it correctly shows attention to the finer points of language, like a craftsperson selecting exactly the right tool for the job.