Brackets (Parentheses) in English

Brackets (also called parentheses) enclose extra information or explanations which interrupt the normal progression of the sentence.

Note:
Full stops, question marks or exclamation marks are usually put outside the brackets (unless the brackets enclose a complete sentence).

Additional Information in Brackets

Additional information is enclosed in brackets if the information is not essential for the understanding of the sentence.

Example: Connor (Amy's boyfriend) bought the tickets.

Note:
Depending on the importance attached to it, additional information can be enclosed in brackets, commas or dashes.

Brackets – not important
Connor (Amy's boyfriend) bought the tickets.

Commas – neutral
Connor, Amy's boyfriend, bought the tickets.

Dashes – emphasised
Connor–Amy's boyfriend–bought the tickets.

see also: → Additional Information in Commas

see also: → Dashes in Summaries and Additional Information

Abbreviations in Brackets

At the first mentioning of an organisation in a newspaper article, both its abbreviation and the spelled-out form are mentioned, one of which is enclosed in brackets.

Example:
   He was an active member of the IOC (International Olympic Committee).
   He was an active member of the International Olympic Committee (IOC).