What do you do when you wish to incorporate a quotation from another source into your own content, but the quotation includes a flaw in spelling, grammar, or the like, or you want to use the quotation selectively? How and whether you amend quoted material depends on the content and the context.
In a formal context, such as a scholarly or other authoritative nonfiction book, if source material is flawed, you have several options depending on the type or extent of nonstandard content. For a simple misspelling or grammatical error, follow the mistake with the interpolation [sic], italicizing the word, derived from Latin, that means “so” or “thus” and indicates that the preceding error is reproduced from the original material; the brackets should be styled in normal roman type.
If errors are ubiquitous, or an obsolete convention such as rampant capitalization is repeated, acknowledge that fact in a brief preceding note in the text, a concise bracketed comment, or a footnote. These strategies are also appropriate to clarify that the writer reproducing the quotation does not condone a controversial remark or an offensive term or comment within it.
What if a passage already includes ellipses and you wish to omit phrases or sentences? Distinguish between the original ellipses and your own, perhaps by enclosing the ellipses you have introduced within brackets and explaining in a preceding note or in a footnote that this treatment indicates introduced, as opposed to original, omissions. If the context does not make clear that original ellipses have not been introduced, insert a bracketed note such as “[Ellipses in original],” but employ this intrusive strategy in moderation.
In such formal content, quotations should preserve spelling, capitalization, punctuation, and treatment such as italicization or full capitalization of a word. However, if an entire sentence or passage originally appeared italicized or in all-caps, you can render it in friendlier type and note in brackets how the material originally appeared. (Also, when introducing italics to emphasize a point, follow that treatment with the note “[Emphasis added.]” Conversely, to clarify that the italics are original, insert the note “[Italics in original.”)
The Chicago Manual of Style supports limited corrections or format changes such as the following:
1. Revision of quotation marks to conform to the prevailing style (such as changing single quotation marks, used in British English, to double quotation marks, standard in American English).
2. Revision of the first letter of the first word from uppercase to lowercase or vice versa as required to integrate the quotation with the preceding text. (It is not necessary to bracket a change in case except in legal writing or textual commentary.)
3. Insertion of terminal punctuation (a period, question mark, or exclamation point) or replacement of existing punctuation to integrate the quotation into the surrounding text.
4. Omission of superscript note indicators, such as numbers or asterisks, when the notes are not retained.
5. Isolated misspellings or typographical errors (but retain “mistakes” when they are deliberate, such as when imitating an illiterate attempt at writing, or when quoting from material written at a time when spelling was nonstandard).
6. Adjustment of indented or centered text to match formatting of the surrounding text.
In less formal contexts, you can employ silent correction, the strategy of simply editing the original material without comment. Writers must used sound judgment, however, in minimizing the alterations and refraining from altering the meaning or intent of the original content. Usually, silent correction should be employed only to correct misspellings or erroneous punctuation. If the grammar of the original material is poor or the material is otherwise problematic, it is probably better to paraphrase entirely or to directly quote only key phrases.
Also, exercise caution when reproducing heavily accented speech. Gonna, wanna, and similar lazy pronunciations need not be reproduced; doing so, or representing mispronunciations such as “nukular,” may be misinterpreted as condescending to the speaker. Silent correction is also appropriate for errors such as flustrated as a confusion of flustered and frustrated.