I often encounter this problem myself, and see that other editors do too. Say, you can see an English message which contains a variable written as ''$1''. In the Translate extension it is not clear what these ('') do represent: the very double quotation marks, or the markup to make a text italic. Thus, the translators often misinterpret those, and sometimes a text like this turns out to be a «text like this» (or vice versa) in the translation to a target language, or text like this turns out to be a «text like this».
- Example of the previously linked English message translated into French or
- This weird case of a message translated into Ukrainian (and this is what it should look like)
A way to fix this would be to separate the single quotation marks more, so that it would be clear that they're meant to make the text italic.
EDIT: I've also uploaded a file for a reference (this is from a Meta-wiki page named "User groups", the original English message is in italic, but that's not obvious for someone using the Translate extension):