* Language evolution is complex: Languages change and evolve over time, making it difficult to trace a direct lineage back to a single ancestor.
* Lack of written records: Many early languages existed before the invention of writing, leaving no tangible evidence of their structure or vocabulary.
* The concept of "oldest" is tricky: Even if we could identify a language with the earliest roots, defining "oldest" is problematic. Do we mean the language with the longest continuous use? The one with the most ancient origins?
What we do know:
* Proto-Indo-European: This is a reconstructed language considered the ancestor of many languages spoken in Europe, Asia, and parts of the Americas. It's estimated to have been spoken around 4500–2500 BCE.
* Proto-Sino-Tibetan: This is another reconstructed language, ancestral to languages like Chinese, Tibetan, and Burmese. It's believed to have been spoken around 4000–3000 BCE.
Important Note: Reconstructed languages are theoretical, based on the study of related languages. They are not directly spoken, but rather a reconstruction of a likely common ancestor.
Instead of focusing on a single "oldest" language, it's more insightful to consider the fascinating history of language families and how they have diverged and evolved over millennia.