As someone who runs QC tasks on a regular basis, I have developed a moral code on how to perform these tasks the best way possible. Learning from your translation mistakes is a rule of thumb, but it is even more rewarding when your job requires you to ruthlessly correct other translators' blunders. Unless a machine is used, translation is done by a human and it is normal to err. You witness a wide range of errors that you can dodge in the future. After years of experience, the pattern becomes very clear and translation mistakes tend to be repetitive. This allows you to put things into perspective, which in-turn makes you proactive and more capable of predicting the problem before it catches you off guard. That being said, I have made a list of the most common translation mistakes that I encounter almost every day.
#1 translation mistakes: neglecting the instructions
Scenario: you sent your translator detailed instructions of the project. For example, a list of your preferred terms to be included in the translation, or perhaps you asked them to leave some terms in English. To your surprise, the translator did not follow the list of terms you provided and did not leave the requested terms in English. Instead, he/she did not even read the instructions, forgot to follow them, or simply made preferential changes to your glossary.
#2 translation mistakes: transferring mistakes into the target language
Scenario: your source text contains inaccurate information. For example, you used the wrong value when you converted centimeters to millimeters, or you misspelled your product's name. Ideally, the translator should automatically realize the mistake and convey the correct meaning. Not fixing the issue is an indicator that the translator is not paying full attention to the content he/she is translating.
#3 translation mistakes: confusing languages
Scenario: you are reading a text in English and it does not sound natural. Instead, it sounds suspiciously like Spanish. No matter how good your languages are, you can sometimes experience language poisoning. Words like "actual", "colegio", "compromiso" can mistakenly be translated as "actual", "college" and "compromise". The phonetic similarity can throw off some translators. Read about serious consequences of false friends on: https://www.old.pangeanic.com/knowledge_center/medical-translation-how-words-can-save-your-life/
#4 translation mistakes: omitting words
Scenario: your translator sent you the translation and, if you understand the target language, you notice that he/she skipped the translation of some terms. Most of the time, this happens because the translator is absent-minded, or because he did not revise his work thoroughly.
#5 translation mistakes: delivering the wrong files
Scenario: your translator is working on several projects simultaneously. Whether all of these projects are related to you or not, he/she can confuse the projects and deliver the wrong files. Apart from the fact that this is highly inconvenient for the client, it also violates confidentiality policies.
#6 translation mistakes: not answering the client's queries
Scenario: you received the translation and you have queries/feedback/request to change some things. Unfortunately, after the project was delivered the translator is not returning any of your calls or answering any of your emails and is completely unavailable to answer any of your questions.
#7 translation mistakes: being afraid to ask questions
Scenario: your text might have some vague phrases. Instead of asking for clarifications, your translator tries to guess the meaning, or conveys the meaning in an equally vague manner.
These are some examples of translation mistakes that truly reflect the reality of the translation world. If you are intrigued and would like to read more about translation mistakes that will make you laugh, you can read about them here: https://www.old.pangeanic.com/knowledge_center/arabic-gone-wrong/.