Here's what we do know:
* English: Her native language.
* French: She was educated in French and could speak and understand it.
* German: It's likely she had some understanding of German, as it was a common language in the royal family in her youth.
There are some reports that she might have had some basic knowledge of other languages like Italian and Spanish, but there's no concrete evidence to confirm this.
It's important to remember that fluency isn't the only factor in language skills. The Queen likely understood and could communicate effectively in a number of languages, even if she wasn't completely fluent.