Many factors, such as word choice, organization, suitability to reader and discourse community, and numerous other rhetorical considerations, influence readers' perception of good writing. The factor provoking instant and powerful abreaction from a reader, however, is often a perceived error in grammar or usage. This study tests extent to which business executives and business communication academics were bothered by selected examples of these questionable usage elements. Results show usage elements that troubled readers most were basic sentence-structure errors such as run-ons, fragments, nonparallel structure, and danglers. Several usage errors, such as use of disinterested for uninterested and use of qualifiers with absolutes such as unique, may be in transition to acceptability. The error of completing a linking verb with an adverbial clause troubled few. Executive readers were bothered less by questionable usage elements, overall, than academic readers, and younger readers less th an older readers. Acknowledging to students that usage changes, clarifying differences between written and spoken dialects, and exemplifying and explaining most bothersome errors (using a minimum of traditional grammar terminology) can help students overcome some weaknesses. Keywords: Usage, Grammar, English Language, Business Writing, Pedagogy In their efforts to write Standard English in business messages, business students rather persistently make certain written-English usage errors. Perceived errors bother readers because, as Shaughnessy (1977) says, they are unintentional and unprofitable intrusions upon consciousness of reader, . . . [demanding] energy without giving back any return in (p. 12). Shuman (1995) remarks, the public is a harsh judge of surface errors in writing (p. 116). At worst, usage errors in business messages can cause misreadings that carry a high price. (Not all business messages with potential legal or financial consequences get reviewed by editors and legal counsel.) Error-prone writers might, for example, inadvertently obligate themselves or their firms financially, compromise themselves or their firms ethically, or erode their own or their firms' credibility. To be sure, not all errors incur serious costs. An error might interfere with meaning but cost nothing, or annoy a business reader but be decip herable with extra effort. Some errors are noticed but do not bother readers much, and some errors pass entirely unnoticed in context. Most of us acknowledge that language is arbitrary, its signification deriving from general agreement of its users, and that language changes with its users' practice. As Nevalainen (1993) says, though, What makes most language changes difficult to observe is their gradual implementation (p. 26). The difficulty of observing is increased because reactions to usage errors differ greatly from reader to reader and can vary with context. Standing in language's midstream, we as teachers are responsible for teaching written English that is correct for our time. It would seem futile to try to persuade students that Standard English of, say, 1930 (which some outdated handbooks still purvey) is still Standard English expected by present and future employers. But what has changed, and what has not? Ten years ago we surveyed executives and academics on 45 questionable usage elements (Leonard & Gilsdorf, 1990) to assess botheration level of these usage elements. The study concentrated on selected grammar and usage lapses that appear again and again in of each year's new crop of students. Our conclusions then were based on assumption that usage lapses bothering fewest readers least are probably those farthest along in process of change from sometime error to acceptable usage. The study we present in this article, also survey-based, follows up that study to see what further changes may have occurred. …