Abbreviations & Acronyms


Knowing when to use the words a, an, or the with abbreviations can be confusing. Here is the rule: Use a when the word begins with a consonant sound, and use an when the word begins with a vowel sound. I hope you repeat saying that rule out loud: 'Use the letter "a" when the word begins with the sound of a consonant, and use the word "an" when the word begins with the sound of a vowel.   In the following examples, you'll find the acronym and the abbreviations underlined:

When to use spaces, when to use periods:

Formal English writing sometimes uses abbreviations for Latin words. You will see them used in legal briefs, medical records, academic essays, reference books, text books, research papers, scholarly journals and other types of materials that are usually written in the formal manner. It is a good idea to become familiar with these if you are learning Business English, or writing academic essays. Some sources say to use these abbreviations only in footnotes and bibliographies.  Other sources say not to use them at all. Whether or not you'll have to use them, it's important for you know their meanings, and how to write them properly. Here is a short list of some of the most common ones:


c or copyright (1949) loc. cit in the place cited; used the same way as ibid.
c. ca. about, around, circa; used with dates (She was born c.1900) ms. mss. manuscript, manuscripts
cf. compare; cf. Magna Carta means: compare this with the Magna Carta N.B. note well
ed. editor, edited, edition n. d. no date; used when the publication or copyright date of a source is not known
e.g. for example; He didn't care for meat, e.g., pork, beef, poultry. (Note the comma before and after e.g.) op. cit in the work cited; used the same as ibid. and loc. cit
et al. and others; also, elsewhere (When studying sociology, one is required to read the classic works: The Golden Bough, et al.)  q.v. which see, whom see; indicates that the reference is within the same source; encyclopedias may use this to direct you to other entries within that same encyclopedia.


following page, pages; (p. 3f. means page 3 and the following page.   pp. 3ff means page 3 and all of the following pages) sic always written lower case, in italics or underlined and used in brackets [sic] after a direct quotation when there is an error in the quote; to show that the person being  quoted made the error, not the person who copied it . In other words, a magazine journalist must show that the person who was interviewed made the mistake in English---not the journalist.
ibid. in the same place; used with a reference that is the same as one previously cited vide see
i.e. that is, or that is to say; note the comma before and after the i.e.: The weather has been very bad, i.e., a dangerous hurricane. ",i.e.," is commonly misused--confused with ",e.g.," "i.e." is used to clarify a thought---to show another way of expressing a thought; "that is to say". It isn't for giving a list of examples. etc. et cetera (and other things) Etc. is not used in formal writing, but is used quite often in informal writing. Use it when you have a lengthy list of items, and you don't want to write all of them. Be sure that the you give the reader some idea of what the unnamed items could be: The spring garden looked lovely with tulips, daffodils, hyacinths, etc., all in bloom. The reader can deduce that the etc. means other spring-blooming flowers. Writing "etc." one time in a sentence is sufficient. Although you will see and hear poorly-educated people writing and saying "etc. etc.", it's a redundancy.

Titles that are written  before a name:

Mrs. mistress (The word mistress is never said, when referring to a married woman. Pronounce Mrs. like missis.)
Mmes. plural of Mrs.  (Used only as a written salutation in some formal letters--not spoken.)
Mr. Pronounced Mister
Messrs. plural of Mr. (Again, used only as a written salutation in some formal letters--not spoken.)
Ms. "Ms." is not an abbreviation, and is written with a period to match Mr. & Mrs. (Sounds like "mizz".) Written and spoken when addressing any woman, regardless of her marital status.
Dr. Doctor (plural is Drs.)
Gen. General (Don't abbreviate military titles in formal writing. It is acceptable in informal writing.)
Prof. Professor (plural is Profs.) Written, not spoken
Rep. Representative (governmental title) Written, not spoken.
Sen. Senator (governmental title) Written, not spoken.
St. Street (St. is also an abbreviation for Saint) Written, not spoken.
Ste. Suite (Ste. also means Saint when used with French names) Written, not spoken.

These are not really titles, but are used as such. Use these abbreviations only in written informal language.


Reverend ( always write The Reverend + his/her last name.)

Hon. Honorable (always write The Honorable + his/her last name.)

Titles that are written after names:


Jr. Junior
Sr. Senior
M.D. or MD Medical Doctor
D.D.S. or DDS Doctor of Dental Science
R.N. or RN Registered Nurse
Ph.D. or PhD Doctor of Philosophy
M.A. or  MA Master of Arts
B.S. or BS Bachelor of Science

 When writing a name that has a title, you must choose one of the two options---not both .

Correct: Dr. George Walters or George Walters, PhD.

Incorrect: Dr. George Walters, PhD

When writing, don't abbreviate a title if there isn't a name following it.  

Correct: I took my sister to the doctor yesterday.

Incorrect: I took my sister to the Dr. yesterday.


When writing, don't use informal American English shortened words. You can use them in your own personal notes, but not in formal writing:


An acronym is formed by taking the first initials of a phrase or compound word and using those initials to form a word that stands for something. LASER (pronounced "LAYzer"), is an acronym for Light Amplification by Stimulated Emission of Radiation. FBI, (say each letter--eff--bee-eye), is not an acronym for the Federal Bureau of Investigation; it is an abbreviation. AIDS is an acronym; HIV is an abbreviation. URL (pronounced "you---are---ell") is an abbreviation for Uniform Resource Locator (World Wide Web address).


If the letters are pronounced as a word (like NASA, LASER), it's an acronym. If each letter is said one by one (as in eff bee eye), it's an abbreviation. Please read that rule again, out loud: If the letters are pronounced as a word, it's an acronym. If each letter is said one by one (as in eff bee eye), it's an abbreviation.

To find more acronyms and abbreviations, try this link:


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