Expressions That Deviate Markedly From the Essay's Style and Tone (KLA 302)

Grammar rules catch broken sentences. Tone is a different kind of rule: it catches sentences that are built correctly but belong in a different piece of writing. Imagine every essay sitting at one point on a dial that runs from casual to formal. A lab report or a museum conservation piece sits near the formal end. A first-person story about a night shift sits near the casual end. Once an essay picks its spot, every sentence has to match it, not just avoid errors.

'The data were pretty bonkers' is grammatically fine. It breaks because 'pretty bonkers' is a casual phrase dropped into a formal report, like someone showing up to a funeral in flip-flops. The fix is never to tone the slang down a little — 'a pretty big change' is still off. The fix is to replace it with language the rest of the essay already speaks: 'a decisive revision of the model' sounds like it was written by the same person who wrote the rest of the report. Tone problems also hide outside slang: talking directly to the reader ('you would be amazed'), vouching for a claim ('believe me'), or being needlessly casual all pull a sentence off the dial even with zero slang words in it.

This sits next to word choice and redundancy questions because all three ask whether a phrase earns its place in the sentence. Tone zooms out one level: it asks whether the sentence earns its place in the whole essay. A narrative essay flips the usual expectation — since it sits low on the dial already, the stiffest, most formal-sounding choice is the one that has fallen off, not the loose or vivid one.