A language is considered "dead" when:
* No native speakers remain. This is the most common definition. While some may still use it for scholarly or religious purposes, it's no longer a living language spoken daily.
* There is no longer a community of speakers. This goes hand-in-hand with the first point. Without a living community, a language cannot evolve or adapt.
However, an unchanging language doesn't automatically mean it's dead.
* Some languages are artificially preserved. This is often the case with liturgical languages like Latin, which are maintained for specific religious purposes. While not actively spoken in daily life, they remain in use for specific contexts.
* Some languages are frozen in time. This can happen when a language is documented but not spoken, or when a specific dialect is preserved for historical or cultural reasons. These languages might not evolve, but they still exist as a record of the past.
The key difference lies in the presence of a living, speaking community. If a language has speakers who use it in their daily lives, it will inevitably change. However, the rate of change can vary widely, and some languages change much more slowly than others.
Examples:
* Latin - A dead language, but still used in some contexts.
* Old English - A dead language, but its influence is clear in modern English.
* Icelandic - Often called the most conservative language in the world. It has changed very little over the centuries, but remains a living, spoken language.
In conclusion, while a language that doesn't change might be considered "stagnant," it doesn't necessarily mean it's dead. It's more accurate to consider a language dead when it no longer has native speakers or a community of speakers.