* No Official Census: There hasn't been a recent and reliable census in Nigeria that specifically tracks language use.
* Linguistic Diversity: Nigeria has over 500 languages, and many people speak multiple languages.
* Hausa as a Second Language: Hausa is widely spoken as a second language, particularly in Northern Nigeria, due to its historical and commercial importance.
However, estimates:
* Significant Population: Hausa is one of the major languages in Nigeria, with a significant population of native speakers.
* Dominant in Northern Nigeria: Hausa is the dominant language in the northern regions of Nigeria.
Conclusion:
It's safe to say that a large percentage of the Nigerian population either speaks Hausa as their first language or is fluent in the language. But a precise percentage is difficult to pin down without a comprehensive and recent census.