Usage of brackets/parentheses (etc) [closed]

Solution 1:

Curved brackets, or parentheses (like these), are used to set off different kinds of interruption to a sentence. Square brackets [like these] are used in a quotation when the words contained in them are not part of the quotation, but are necessary for the sense. Curly brackets, or braces {like these}, are rarely used in normal writing. They are mostly reserved for specialised texts.

Solution 2:

• Brackets — [] — are used to enclose "meta information" regarding text — text that is used to explain other text from an outside point of view. As an example, brackets can be used to give context to a direct quote by replacing or adding words that were not actually said in that exact manner, yet help to understand the meaning.

  I don't know, [the crazy monkey] bothers me.

  The term sic is generally put in brackets, expressing an intentionally recreated mistake in a quote.

  I ordered my sandwich with cheeze [sic] and ham.

  It can also be used to show citations, as done on Wikipedia.

  Southpaw Hare is an awesome dude. [15]

• Parentheses — () — are used mainly for asides or secondary thoughts that step away from a main thought before returning.

  There is a big difference between rabbits and hares (although you can use 'bunny' to refer to either of them).

• Braces — {} — don't have any mainstream use in ordinary English — they are used in various technical fields for special expressions.

Most information from Wikipedia's page on Brackets.

Solution 3:

Perhaps it would be better to address parentheses as parts of sentences before discussing the punctuation involved; it can be confusing that the word has such a dual role. At http://josecarilloforum.com/forum/index.php?topic=459.msg1503#msg1503 is:

... information ... set off by the punctuation marks — whether by commas, dashes, or parentheses — is called a parenthetical [or simply parenthesis, EA], and its distinguishing characteristic is that the sentence remains grammatically and semantically correct [and felicitous] [disregarding minor tweaks of a/an conversion and punctuation] even without it. A parenthetical is basically added information; however, it isn’t necessarily optional or semantically expendable. It may be needed to put the statement in a desired context, to establish the logic of the sentence, or to convey a particular tone or mood for the statement. In fact, the punctuation chosen for a parenthetical largely determines its optionality or importance to the statement.

Carillo goes on to discuss the choice of commas, dashes, or parentheses to set off parentheses (parentheticals). He may be over-analytical; it is true, however, that commas signal the least abrupt interruption to the matrix sentence (apart from zero punctuation, which can be used in the odd example) and dashes the most abrupt.

Mark Nichol (at http://www.dailywritingtips.com/8-types-of-parenthetical-phrases/ ) discusses different uses of parentheticals, though parentheses would not be preferred over commas say for all types in all situations.

Nowadays, there is a move towards minimal punctuation, and zero offsetting punctuation around a parenthetical where confusion isn't introduced is a real option:

• I have decided that if it is sunny tomorrow I will go to the park.

This flows more smoothly than

• I have decided that, if it is sunny tomorrow, I will go to the park.

But either is acceptable. The version using brackets

• I have decided that (if it is sunny tomorrow) I will go to the park.

looks ungainly; the conditional clause does not merit such emphasis.