A

a, an

When writing the indefinite article before an abbreviation write it as you would naturally pronounce it even if this means you’re writing “an” followed by a consonant or “a” followed by a vowel. Examples: an MBA; a UK authority.

acknowledgement

Acknowledgement rather than acknowledgment.

ad hoc

Not hyphenated, even when used adjectivally.

advance, advanced

Advance means “ahead of time”. Advanced means something like “highly developed”. So it’s advance notice (not advanced notice) and advanced features or functionality (not advance).

adviser, advisor

Use the –er spelling rather than the –or spelling.

affect, effect

Sometimes confused.

  • Effect is usually a noun and it refers to the change resulting from some cause. “The effect of inflation on savings.” It can also be a verb meaning to cause or bring about. “Effect minor repairs as necessary.”
  • Affect is usually a verb and most commonly means to exert an effect on, or to influence, as in “an untidy office can affect your productivity”. It can also mean to put on a pretence. Less commonly, affect can also be a noun in the field of psychology, meaning emotion or desire as influencing behaviour.

afghani

The (Afghan) afghani (Af) is the currency of Afghanistan. The usage of Afghani to mean a person or thing of, from, or related to Afghanistan is viewed as improper. Say Afghan or Afghanistani.

all right, alright

“Alright” isn’t really all right. It’s best to stick to the two-word form, as the single-word form is widely regarded as incorrect.

all together, altogether

  • All together (two words means) “in a group” or “in total”. You could say, “They left in one taxi, all together.” You could also say, “That comes to ten pounds all together.”
  • Altogether (one word) means “completely”. Are you altogether clear as to the distinction?

alternate, alternative

An alternative is a substitute; use alternate only to mean “every other”, as in “alternate months”.

analogue

Analogue in preference to analog.

and, &

Write the word “and” in full in preference to the ampersand (&) except where it’s a company or brand name or some term that is officially written with the ampersand, or a term widely abbreviated thus, such as R&D; M&A.

and/or

Write it with no space before or after the slash. But consider whether you can convey the same meaning by using and or or alone.

appraise, apprise

  • Appraise means to assess the value or quality of something, or to set a value on an item. The term appraisal is also commonly used in the sense of a regular review of an employee’s job performance. The word is related to praise.
  • Apprise means to tell or inform, perhaps in a formal sense. You can’t appraise someone of a fact; you can only apprise them of it.

Asia-Pacific region

autumn

Not capitalised.

average life expectancy

See life expectancy.