Basically, Bothii was the language which has normally spoken by the Uthgardt barbarian tribes and also the inhabitants of Hartsvale.
This Bothii was treated by some like a dialect of the Illuskan. So, this bothii itself consisted of two dialects, such as one was spoken by the Uthgardt, and another was by the Hartsvalers.
Attributes Of Bothii DnD 5E Language
Language Family: Faerûnian languages
Language Group: Illuski
Common Dialects: Uthgardt, Hartsvaler
Influenced by: Illuskan
Spoken in:Savage Frontier
Spoken by: Uthgardt, Hartsvalers
Based on: Nordic