Oxford English Dictionary

quote, verb. To reproduce or repeat a passage from (a book, author, etc.); to repeat a statement by (a person); to give (a specified person, body, etc.) as the source of a statement.

quotation, noun. A passage quoted from a book, speech, or other source

Note that the slightly informal noun 'quote' is often used for 'quotation'.

In the extract below, from a PhD thesis from the LU Institute of Economic Research, a quotation is used to define the meaning of a specific term. The writer has chosen to explain the term he uses by quoting the definition given by the researcher who coined the term:

Major criticism was led by Alter (2003a; Alter, 2003b), who argued that although the IT artifact was an important component of IS research, IS were best regarded as organizational work systems supporting other organizational work systems. It was in the support of the IS work system that it found its value, thus it is from this perspective that it should be studied (Alter, 2003a). Alter's term 'work system' refers to "a system in which human participants and/or machines perform a business process using information, technology, and other resources to produce products (and/or services) for internal or external customers" (Alter, 1999).  

(Henningsson, 2008, p. 31)

The following extract comes from a Master's thesis in Theology.

In the passage below, a quotation is used in order to back up and to substantiate the claim that is being made by the writer.

Example:

Augustine is sometimes criticized for failing to properly distinguish God from the world in positing God as the highest being, or as idipsum, thus inscribing himself within the Western tradition of ontotheology.⁷¹ The Pseudo-Dionysius is then invoked as the one who overcomes ontotheology by insisting with neo-Platonism that God must be beyond being. In my opinion this is mistaken since it operates with too literalistic an understanding of the terms: pace Heidegger, it is not enough to find the word "being" connected somehow to God to justify an accusation of ontotheology.⁷² What is important is how the words are used and their intention. In the case of Augustine it is clear that he preserves the Christian distinction between the Creator and the world: "For every substance that is not God is a creature, and that is not a creature is God."⁷³ In fact, Augustine holds that properly speaking only God really is; God is not so much beyond being as we are below it, created things do not quite attain to being.

[...]

71 Marion, J.-L. (1991), God Without Being Hors-Texte, The University of Chicago Press, p. 73, 215, note 50.
72 Marion, J.-L. (2001) De surcroît: études sur les phénomènes saturés, Presses Universitaires de France, p. 175.
73 De Trin. 1.9

(Nordlander, 2008, p. 24)

Below is a link to an article from the Journal of Communication on the importance of contextualizing quotations. One example that is brought up is the so-called  "yew tree controversy," in which former US Vice President Al Gore was quoted out-of-context by a conservative columnist, as having argued than the preservation of trees was more important than to save human lives.

The "yew tree controversy" example is found on pages 332-334 of the article, starting with "Contextomy is also a common spin tactic among unscrupulous political journalists..." at the bottom of page 332.

McGlone, M. S. (2005) Quoted out of context: Contextomy and its consequences. Journal of Communication, 55, 330-346. Retrieved from Wiley. [Access article via LibHub]

Note that in English writing, the typographical quotation marks look different from Swedish quotation marks. If set to English language settings, MS Word will automatically format quotation marks correctly:

‘quotation’   “quotation”

The quotations used for our examples below come from Barack Obama's inaugural speech, as transcribed in The New York Times.

Short quotations are given within inverted commas in the running text, as in the following sentence:

Example:

US President Barack Obama's inaugural speech opened in the following way: "My fellow citizens: I stand here today humbled by the task before us, grateful for the trust you have bestowed, mindful of the sacrifices borne by our ancestors" (The New York Times Jan 20, 2009).

Long quotations are often set off from the running text into separate blocks of text, so-called block quotations:

Example:

In his inaugural speech, US President Barack Obama referred to some of the challenges he was facing:

That we are in the midst of crisis is now well understood. Our nation is at war against a far-reaching network of violence and hatred. Our economy is badly weakened, a consequence of greed and irresponsibility on the part of some but also our collective failure to make hard choices and prepare the nation for a new age. (The New York Times Jan 20, 2009).

Oxford English Dictionary

ellipsis, noun. The omission of one or more words in a sentence, which would be needed to complete the grammatical construction or fully to express the sense; concr. an instance of such omission.

Note the plural form of ellipsis: ellipses

Square brackets can be used for clarity, to add information that the writer considers to be necessary for the understanding of the quotation.

The following example comes from an article in Victorian Literature and Culture. For reasons of clarity, the writer has added a numeral to the name of the king who is mentioned in the piece of text that she is quoting:

Example:

Cast off by her husband, the Prince Regent, and sent into exile in 1814, Queen Caroline had returned to England in June 1820 to "demand her rights as Queen and to contest George [IV]'s demands for divorce, and accusations of adultery" (Wood 149).  

(Ledger, 2004, p. 578)

If the quoted text is too long, it is possible to shorten it with the help of an ellipsis. The writer must indicate this with square brackets where a chunk of text has been removed.

In the example below, from the British Journal of Sociology of Education, a Swedish governmental report is being quoted. The writer first introduces the quotation and then follows up with a comment. The ellipsis in the quotation was probably inserted in order to cut down on the length of the quotation.

Example:

Against this background, the report sees a number of crucial consequences for the way 'immigrant parents' bring up their children.

Swedish norms and values of raising children often invoke fear. […] Uncertainty regarding what the consequences might be if they give in to their children's demands leads many parents to strengthen and exaggerate the ideals of child-rearing that prevail in their home country. (SOU 1997b, 194ff)

Throughout, the report makes a categorical distinction between 'Swedes' and 'immigrants', 'Swedish' and 'un-Swedish', as if these categories were immutable, natural and self-evident.

(Dahlstedt, 2009, p. 199)

Square brackets containing words or morphemes can be used if the grammatical structure of the quotation does not fit into the running text.

The following example has been taken from an article from Hispania. The article deals with a novel called La sombra by the Spanish writer Benito Pérez Galdós. In the extract, the article writer has used square brackets to accommodate the verb tense of the quotation:

Example:

La sombra evokes the classical British Gothic novel, which "concern[s] itself with psychological problems, used to dramatize uncertainty and conflicts of the individual subject in relation to a difficult social situation" (Jackson 97).  

(López, 1998, p. 510)

Comment: López here quotes a critic called Jackson. In original, Jackson's statement about the genre of the Gothic novel looks like this:

It is progressively turned inwards to concern itself with psychological problems, used to dramatize uncertainty and conflicts of the individual subject in relation to a difficult social situation. (Jackson, 1981, p. 97).

When quoting parts of this sentence, López thus had to change the verb form from 'concern' to 'concerns' in order to make the quotation fit with her text.

Note that different reference styles have different ways of indicating that an emphasis has been added. The example below is written in APA Style. Other styles have slightly different ways of indicating added emphasis; in MLA, for instance, the parenthetical reference would be the place to indicate that emphasis has been added.

In Usborne's article on meerkats, these animals are described as almost-human: "They are the little guys with big hearts [italics added] whose struggle for survival and fierce sense of family loyalty not only fascinates scientists and seduces film-makers, but also offers a model of duty and fortitude for us all" (2009, para. 2).

Mistake in original text

The example below comes from a book review. In order to illustrate what the book is about, the reviewer quotes from the book.

Since there is an error ("economic reforms takes" instead of "economic reforms take") in the passage that is being quoted, the reviewer has added [sic] after the error in the quotation. This signals that the error exists in the original text, and that the reviewer is aware of it.

In this case, the mistake can be explained by poor proofreading; the reviewer actually states that "it is hard to find flaws (other than editorial) in this carefully crafted and well-argued book" (Falleti, 2006, p. 414).

Example:

In this book, Erik Wibbels explores the "federal collective action problem" (pp. 47, 62). Because in federal countries national and regional leaders answer to different constituencies, their electoral interests and preferences toward socially costly reforms might conflict. Market economic reforms constitute one type of such measures. As Wibbels argues, in crisis-ridden federations, "economic reforms takes [sic] on the quality of a public good requiring the individual regions to cooperate, whereas it is more rational for each career-oriented politician to avoid the costs associated with austerity" (p. 27).

(Falleti, 2006, p. 414)

Irregular spelling

Sometimes, writers wish to stress that the spelling used in old documents has not been wrongly reproduced.

The quotation below is the opening sentence of an article from Health Education Research on early-seventeenth-century views on the use of tobacco. The writer wants to make clear that the book title does indeed look like this, although the spelling would be different today.

Example:

Late in the reign of Queen Elizabeth I, a treatise against tobacco, entitled Work for Chimny-Sweepers or A Warning for Tabacconists [sic], was published in London (Philaretes, 1602).

(Charlton, 2005, p. 101)

Comment: In essays or articles focusing on old texts, or text using unconventional spelling, [sic] is usually not inserted, as the reader can be assumed to be familiar with spelling conventions of the era or culture.