An acronym is an abbreviation made from the initial (first) letters of a group of words (and pronounced as a word), like this:
Sometimes only the more important first letters are included:
And sometimes the first two or three letters of a word may be used:
Here are some more examples:
|Aids||acquired immune deficiency syndrome|
|laser||light amplification by stimulated emission of radiation|
|NASA||National Aeronautics and Space Administration|
|PIN||personal identification number|
|quango||quasi-autonomous non-governmental organization|
|scuba||self-contained underwater breathing apparatus|
|sim||subscriber identification module|
|TEFL||Teaching English as a Foreign Language|
|UNESCO||United Nations Educational, Scientific and Cultural Organization|
|vat||value added tax|
Generally speaking, acronyms are not punctuated at all. There is no need to use full stops/periods.
If the acronym's full form uses capital letters, then the acronym usually uses capitals too (National Aeronautics and Space Administration → NASA). Some acronyms may be written with the first letter uppercase and the rest lowercase (acquired immune deficiency syndrome → Aids). Many acronyms have developed into words in their own right and may use entirely lowercase (subscriber identification module [card] → sim [card]).
Whether to use capitals or not is often a matter of style. If in doubt over the name of an organization (for example NASA or Nasa?) you can usually follow the organization's preferred style found on its website. For more general acronyms, a good dictionary will usually show the standard form.
Note that some acronyms can also be initialisms. For example, the abbreviation for Value Added Tax (or value added tax) is:
- sometimes written VAT/V.A.T. and pronounced as letters (/vee-ay-tee/) —initialism
- sometimes written VAT/vat and pronounced as a word rhyming with cat —acronym
All acronyms can be pronounced as words, and many of them have indeed become dictionary words in their own right.
write and say: Aids - laser - NASA - PIN - quango - scuba - sim - TEFL - UNESCO - vat