Native speakers can judge whether a sentence is an acceptableinstance of their language. Acceptability provides a means ofevaluating whether computational language models are pro-cessing language in a human-like manner. We test the abilityof language models, simple language features, and word em-beddings to predict native speakers’ judgments of acceptabil-ity on English essays written by non-native speakers. We findthat much sentence acceptability variance can be captured by acombination of misspellings, word order, and word similarity(r = 0.494). While predictive neural models fit acceptabilityjudgments well (r = 0.527), we find that a 4-gram model isjust as good (r = 0.528). Thanks to incorporating misspellings,our 4-gram model surpasses both the previous unsupervisedstate-of-the art (r = 0.472), and the average native speaker(r = 0.46), demonstrating that acceptability is well capturedby n-gram statistics and simple language features.