What 7 languages did Nikola Tesla speak?

There's no evidence to suggest that Nikola Tesla spoke seven languages. In fact, there is limited information on how many languages he actually knew. Here's what we can say for sure:

* Serbian: His native language.

* Czech: He was fluent in Czech, as his mother tongue was a dialect of Serbian closely related to Czech.

* English: He was fluent in English, having emigrated to the United States and lived there for most of his adult life.

* French: He likely had some knowledge of French, as it was a common language of science and diplomacy during his lifetime.

* German: Some sources suggest he may have had basic knowledge of German, but this is not confirmed.

It's unlikely he was fluent in any more than these.