Language Fundamentals

Prepositions at Sentence End

Modern usage allows ending sentences with prepositions when it sounds natural.

Last updated

What & why

What it is
The practice of letting a sentence or question end with a preposition, as in What are you working on? Despite a long-standing prohibition, it is grammatically acceptable in modern English and frequently the most natural phrasing. Rewriting to avoid it (On what are you working?) can produce stilted, overly formal results. The guideline is to keep the ending preposition when it reads naturally and recast only when doing so genuinely improves clarity.
Why it works

Everyday English routinely ends questions and clauses with a preposition, so that order is what listeners expect and parse without effort. Rearranging a sentence to keep the preposition early (For what are we waiting?) forces an unusual word order that sounds formal and stiff, and the novelty itself costs a beat of processing. Matching natural spoken order keeps phrasing fluent and unobtrusive, so attention stays on the question rather than on the contortion used to dodge an outdated rule.

Before & after

Before

“About what are you concerned?”

After

“What are you concerned about?”

When you’ll use it

Client meetings: "Which project are you working on?" (natural vs "On which project are you working?")

Team discussions: "What are we waiting for?" (natural vs "For what are we waiting?")

Performance reviews: "What should we focus on?" (natural vs "On what should we focus?")

Strategic planning: "Which market are we competing in?" (natural vs "In which market are we competing?")

Pro tip

Choose the version that sounds more natural to your audience.

Questions & answers

Can I end sentences with prepositions in business writing?

Yes, ending sentences with prepositions is acceptable in modern business writing when it sounds natural and clear. 'Which project are you working on?' is better than 'On which project are you working?' Prioritize clarity over rigid rules.

When should I avoid ending sentences with prepositions?

Avoid it in very formal documents, when addressing conservative audiences, or when you can rephrase naturally without losing clarity. However, never sacrifice clarity or create awkward phrasing just to avoid ending with a preposition.

How do I handle prepositions in formal business presentations?

In formal presentations, you can often rephrase naturally: 'Which challenges do we face?' instead of 'Which challenges are we dealing with?' But don't force awkward constructions. Natural, clear communication always takes priority.

Learn more

MLA Style Center
The Chicago Manual of Style (Q&A)
Grammar Girl (Quick and Dirty Tips)

Practice this concept

Practice clearer communication

Improve how you sound by practicing real speech patterns with AI analysis.

Try the AI Speech Coach