While it's widely used and understood, it's generally considered less formal than its more formal counterpart, "although".
Here's why:
* Formal writing: In formal writing, like academic essays or legal documents, "although" is preferred for its more precise and elevated tone.
* Informal writing: In informal writing, like emails, blog posts, or conversations, "even though" is perfectly acceptable and often sounds more natural.
Essentially, "even though" is considered more casual and less formal than "although".