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Correct and Preferred Usage

Roxanne K. Young

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The article a is used before the aspirate h (eg, a historic occasion) and nonvocalic y (eg, a ubiquitous organism). Abbreviations and acronyms are preceded by a or an according to the sound following (eg, a UN resolution, an HMO plan). (See also 14.8, Abbreviations, Agencies and Organizations.)

a hypothesis [h sound]

a hematocrit [h sound]

an ultraviolet source [u sound]

an honorarium [o sound]

a WMA report [d sound]

an MD degree [e sound]

a UV source [y sound]

an NIH grant [e sound]

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