Sometimes there’s a glitch somewhere in the system and you might receive a task that isn’t designated as the right language pair. This doesn’t happen very often, but when it does all you need to do is skip the task and mark it as the wrong language pair. This means we can take it out of circulation and try to identify the problem.
Even if you are able to complete this task because you speak the language in question, you should always report it. This is because it won’t have the correct glossary and clearance and could cause massive problems for us, but also because it will count against you if it comes up for evaluation.
There are a couple of very limited circumstances where there may be mixed languages in a text which we will allow, for example email signatures or things like "sent from my iPhone". These are okay to leave in whatever language they were in already, but they should never have anything to do with the main body of the text, nor should they affect the understanding of the person who is going to be reading your text when it's finished. Remember that the reason we're translating is because the person in question doesn't speak the source language!