On several occasions I had to completely rewrite translations because of grammatical and contextual errors in the translation. Explaining the context in which things are used, including giving the translator a product demonstration, helps to improve the accuracy of the translation. Unfortunately, this rarely happens because translation companies discourage communication between the client and the translator. They fear that communication back and forth between client and translator will cause the job to run over budget. Why spend a fortune to have things translated incorrectly when you can get it translated incorrectly for free.
Computers can translate much more quickly and cost effectively than human translators.
If the general meaning of the text is all you need, then use one of the free translation sevices available on the Web. Here are a couple. It will translate text passages up to about forty sentences at a time. Babel Fish will also translate entire Web pages. It will let you insert accent marks and tildes into the text to be translated.