Prescriptive approach: an approach to grammar that has rules for the proper use of the language, traditionally based on Latin grammar, in contrast to the descriptive approach.
That was an approach taken in eighteenth-century England by grammarians who set out rules for the “proper” use of English.
You must not split an infinitive.
You must not end a sentence with a preposition.
Following these types of rules, traditional teachers would correct sentences like:
Who did you go with ? x
With whom did you go ? v
making sure that the preposition with was not at the end of the sentence ( Although in real-life communication, both of them are correct )
Mary runs faster than me to Mary runs faster than I
Me and my family to my family and I
In ‘proper’ English writing, one should never begin a sentence with and