Uttar Pradesh is the core of Hindi-Heartland that comprises states like Bihar, Madhya Pradesh and Rajasthan. Therefore it is but natural that Hindi is the Lingua Franka of this state. In fact, the accent that is spoken in Uttar Pradesh is the standard accent of the Hindi language.
The second most spoken language is Hindustani. Actually Hindustani is
the language that is spoken by the masses whereas the Hindi is largely
confined to administrative usage. Broadly now days, Hindustani if
written in 'Devanagri' script is called Hindi where as if the same is
written in 'Nastaliq' script then it is termed Urdu. Uttar Pradesh has
produced numerous poets and laureates both in Hindi as well as Urdu. For
years these people have ruled the roost.
Apart from that, Awadhi is another popular language. The language is
the Lingua Franka of the masses, particularly rural population, in Oudh.
The language is a hearty mix of Urdu and Khadi Boli. This language was
propagated by popular Sufi poets of their time, particularly Amir
Khusrau. Bhojpuri is another popular language in Uttar Pradesh. In fact
according to the latest census report, Bhojpuri is the most spoken
language in Uttar Pradesh after Hindi. The speakers of this language are
mostly confined to 20 odd districts of Eastern Uttar Pradesh.
'Braj Bhasha' is the language of Lord Krishna. This language is mostly
spoken in regions around Mathura and Vrindavan. This language is
considered to be very sweet and lyrical. There are other minor languages
too such as Gujari, Haryanvi and Bundeli but these are extremely
localized and confined to particular communities.