it weren't گرامر

Question

سلام دوستان من داشتم یه فیلم میدیدم که به این جمله برخوردم  حال سوالم اینجاست چرا همرای it از were  استفاده شده 

Policeman: Sorry, ma'am, there ain't no smell of gas.

Man: It weren't gas, officer. I seen it. It was a gigantic, huge hippop... [Newt passes behind him, waving his wand] ...gas.

[The whole crowd starts yelling "gas" in agreement.]

 

Answer 1

مشخصا یه لهجه غیر استانداره، از ain't معلومه