This is an interesting video by TED-Ed focusing on the topic of “Grammar”. There are two schools of thoughts, Prescriptivism and Descriptivism.
Prescriptivism advocates following the rules of English so that sentences are grammatically correct. This will be applicable during business meetings (formal context) and helps to make communications easier between non-native speakers from different countries.
Descriptivism describes how people use English in different ways and how we structure our views on the world.
Video credits: TED-Ed, Does grammar matter? – Andreea S. Calude