As in many technical products, to one degree or another, the purchaser of a translation has little or no ability to assess the quality of the text until it is made public since it is in a foreign language in many of not most cases. Many an author has only discovered what the foreign reader actually read only after the translated book was published. In fact, the purchaser of a translation must trust that the translator did a professional job, which is both uncomfortable and not always true. Lacking the required knowledge of the target language, purchasers need some parameters to ascertain whether the target text is substandard and requires review.
A short spellcheck of the document can reveal many serious flaws. First, it can highlight real spelling errors, which should have been fixed before delivery. Second, it marks capitalization issues in translation. For example, in French, last names and locations are capitalized, i.e., M. Henry JONES from RENNES, as compared to English where such practice never occurs, e.g.., Mr. Henry Jones from Rennes. Furthermore, punctuation interference is revealed. For example, again in French, two spaces are placed after a colon while in English there is only one, e.g., Grade: 70 as compared to Grade: 70. Likewise, spellcheck will mark sentences that fail to comply with the punctuation rules of the target language since the use of commas and periods varies to one degree or another from one language to another. Finally, spellcheck may identify a grammar issue in terms of form, including gender and number, and tenses. For example, while in many languages, a subordinate clause in sentence in the future is also in the future, in English, the secondary verb in the present: I will call you when I wake up. Spellcheck can identify these signs of poor work.
A visual check can also identify some red flags, especially when working between left to right and right to left languages or languages with different alphabets. The presence of words left in the original language without a specific request to do so should beg clarification. When working between languages going in different directions, it is advisable to look for the proper placement of punctuation such as periods and greater/less than signs, symbols such as trademark and copyright, and parentheses. The customer should carefully check the numbers not only to see if they were miscopied, which is critical in itself, but also whether the appropriate punctuation mark was used to divide the whole numbers and decimals. For example, 500,700.05 in English is 500.700,05 in French. The customer can easily identify these issues.
Finally, if the customer has some knowledge of the target language, which is common in regards to English, it is advisable to read the text out loud. If the sentences sound terrible or word for word like the original, the translator may have been too loyal to the text. Any use of non-localized terminology or incorrect terminology is a clear read flag. For example, a medical ethics committee in the United States is a Helsinki committee in Israel while a fan club in English is not club de ventilateurs in French. Good translators think.
The presence of any these issues does not necessarily mean the translation is terrible but does justify having the text read by a native speaker knowledgeable in the subject area. To be clear, requesting this service from non-natives, regardless of their level, will probably lead to false positives as their knowledge of the written language is generally insufficient to properly identify the issues. However, if a native speaker provides a negative assessment, the client is justified in returning the product to the translator or agency for review. Something probably is rotten in the kingdom of Denmark.