How do I quote a source in another language in an English thesis?

The decision rests on what the quotation is doing. Most quotations carry content: this author said this thing, and you are reporting it. There the reader needs the meaning, so the translation belongs in the flow of the argument and the original goes below for anyone who wants to verify.

A minority of quotations carry form. When your analysis turns on a particular word, a rhetorical structure, or a term that has no clean equivalent, the original is the evidence and the translation is the aid. Then the original goes in the text and the translation follows in brackets or a footnote.

Do not silently translate and present the result as the author's words without saying so. A translation is an interpretation, and a reader who cannot see that a choice was made cannot evaluate it. Saying "my translation" costs two words and removes the problem entirely.

Where a published translation exists, decide which version you are actually using. If you read the translation, cite the translation, with its own translator and pagination. If you read the original and prefer your own rendering, cite the original and note that the translation is yours. Mixing the two, quoting a published translation while citing the original's pages, produces a reference nobody can follow.

Check every translated quotation against the page it came from before you submit. A systematic review of quotation accuracy screened 559 studies, included 28, and found pooled rates of 11.9 percent major errors, 11.5 percent minor errors, and 25.4 percent total errors (Jergas and Baethge, 2015, p. 1). The same review attributes part of that failure to authors reading a paper according to what they expect it to say rather than what it says, with time pressure and rhetorical convenience adding risk (Jergas and Baethge, 2015, p. 14). Translation multiplies that exposure, because the wording you print is one you produced rather than one you copied.

Do I give the original, the translation, or both?

Both, for anything you quote directly. For short phrases, put the original in brackets after the translation. For longer passages, footnote the original. For paraphrases, the translation alone is fine, since the specific words are not what you are relying on.

Length is the practical constraint. A thesis where every quotation appears twice in the main text becomes very hard to read, which is why footnotes carry the originals in most humanities work.

For non-Latin scripts, follow your discipline's convention on transliteration, and be consistent. Some fields expect the script itself, others expect a standard romanization, and a few expect both.

Keeping the original available matters most where a passage is contested or where your reading turns on a single term. Across the investigations pooled in the quotation-accuracy review, major error rates ranged from 2.2 percent to 55.0 percent and total error rates from 6.7 percent to 83.0 percent, with medians of 11.5 percent and 22.5 percent (Jergas and Baethge, 2015, p. 5). The review also records an older convention of counting a quotation as accurate when the source supported its general sense, even if the precise wording was not established (Jergas and Baethge, 2015, p. 11). For a thesis, treat that as the line you must not cross, since a rendering that captures the gist is a paraphrase and belongs in your own sentence, not inside quotation marks.

How do I cite my own translation?

State that the translation is yours, once at the first instance with a note saying all translations are your own unless stated, or after each quotation in brackets. Your translation is still a quotation of the source, so it keeps the original's citation and page number.

The blanket note is cleaner for a thesis with many translated quotations, and it goes in the front matter or at the first instance. Where you use a mix of your own and published translations, mark the exceptions individually rather than relying on the reader to track it.

If a translation choice is contestable, and in specialist work some will be, a short footnote explaining the choice is worth more than a defensive paragraph in a viva. Examiners in translation-heavy fields notice which candidates thought about this.

Say who or what produced the translation, including a machine tool or a colleague who helped. A study of non-English studies in Campbell reviews found cost, time, funding, and the absence of external language resources to be the main barriers, with professional or volunteer translators, translation software, English abstracts, training, and guidelines named as the resources that helped (Neimann Rasmussen and Montgomery, 2018, pp. 7-8). The same study reports that major review guidelines told authors to decide language questions case by case, or to avoid language restrictions, while offering little practical advice on how (Neimann Rasmussen and Montgomery, 2018, p. 2). So expect no rule to hand you the answer, and write down the decision you made instead.

Both studies limit what they can settle for you. Neimann Rasmussen and Montgomery note that thin language resources push teams onto whatever skills they happen to have, which can lose key data and introduce bias, and they say the interpretation needs further assessment (Neimann Rasmussen and Montgomery, 2018, p. 1). The quotation-accuracy review rests almost entirely on English-language literature, with only two Dutch papers and one German one, so its error rates describe a habit rather than a measured effect of translation (Jergas and Baethge, 2015, p. 16). The practice they support is narrow and worth keeping: verify the passage, keep the original where wording carries the argument, and name the translator.