Conversation so far:
What were the languages of the Naga people?
Naga people speak over 89 different languages and dialects, mostly unintelligible with each other.
However, there are many similarities.
Do they have any language in common?
Per Grierson's classification system, Naga languages can be grouped into Western, Central and Eastern Naga groups.
Who makes the Western Nasa groups?
The Western group includes among others Angami, Chokri, Khezha and Rengma.
Who makes the central naga groups?
The Central Naga group includes Ao, and Lotha .
Who makes the eastern Nasa group?
Eastern group includes Konyak, Phom, Sangtam, Khiamniungan, Yimchunger and Chang tribes.
What was the impact of the different languages spoken?
The diversity of languages and traditions of the Nagas results most likely from the multiple cultural absorptions that occurred during their successive migrations.
Where did they migrate to?
According to legend, before settling in the region, these groups moved over vast zones, and in the process, some clans were absorbed into one or more other tribes.
Are there any other interesting aspects about this article?
In 1967, the Nagaland Assembly proclaimed English as the official language of Nagaland and it is the medium for education in Nagaland.
Which other language do they speak apart from English?
Other than English, Nagamese, a creole language form of the Assamese language, is a widely spoken language.

Question: But does that mean English is the only official language?
Self-contained rewrite: English is the only official language the Naga people speak?