If you’re just looking to get the gist of an article or trying to order food in a foreign restaurant, Google Translate is a convenient solution; plus it’s free. But here are a few problems you might run into if you’re dealing with documents that require more accuracy.

1. It doesn’t always do well with idioms or marketing material.

Idioms are expressions used naturally by native speakers of a given language. They are never to be translated word for word. When human translators encounter an idiom, they are able to recognize it as such and look for the equivalent in the target language; this is a task Google Translate hasn’t quite mastered yet.

Here are a few nonsensical results produced by Google Translate:

C’est pas la tête à Papineau It’s not the head in Papineau He’s no rocket scientist
Rouler quelqu’un To ride someone To take someone for a ride
Passer un savon à quelqu’un To pass a soap to someone To tell someone off

Similarly, it won’t necessarily do a great job with your marketing or advertising material. A sentence on a communication firm Website reads, “Nous comprenons vos besoins. Nous vous aiderons à vous surpasser,” which Google Translate renders as, “We understand your needs. We will help you exceed you.” In this example, it’s clear that Google didn’t know how to process the expression “se surpasser.” A human translator might have produced the more elegant, “We will help you reach new heights.”

2. It won’t necessarily indicate language level.

Many languages have both a formal and an informal level meant for different audiences and contexts. For instance, we don’t greet our boss the same way we greet our best friend. Google Translate might give you a perfectly fine colloquial expression that may, however, be inappropriate for a situation that calls for a bit more decorum.

3. It will need to be carefully revised.

There’s no way around it, if you use Google Translate you will need to comb through the translated document to eliminate potentially embarrassing errors.

4. It might be sexist.

Recent reports by some users of Google Translate indicate that it might have a gender bias. When translating from Turkish to English, a gender-neutral language with no “he” or “she,” all the stereotypically male occupations, such as engineer or doctor, came out with the pronoun “he,” while job traditionally performed by females (nurse or cook) were associated with the pronoun “she.” Go figure!

A final thought: A 2014 study found that Google Translate had a 57.7% accuracy rate when processing medical information. Naturally, the researchers concluded that it “should not be trusted for medical communications.” So if you or a loved one needed emergency care in another country, would you have Google translate your medical information? I don’t think so!