Sparky: English grammar is really difficult.
Mr.Maru: Why is that?
Sparky: well, sometimes I read a grammar rule and study it but people don't speak that way.
Mr.Maru: Can you give me an example?
Sparky: Using their, a teacher told me I shouldn't use their for a single person, but people use it all the time.
Mr.Maru: Yes, they/them/their is often used to talk about a single person. Some people do think it is wrong though.
Sparky: Why?
Mr.Maru: There are different kinds of grammar for English you can use - one is descriptive and one is prescriptive.

What is Descriptive Grammar?

Language is constantly changing. It is a unique organic system that is never static. English has become an important language because it has evolved and adapted over several hundreds of years to become what it is today.

As the language changes the rules for the language change as well. If the majority (50% or more) use the language one way that becomes the new rule. Changes happen slowly because there are over a billion English speakers in the world, but they do still happen.

Descriptive grammar describes how grammar is actually being used. It can also be called colloquial grammar. When speakers start to change the language, descriptive grammar helps to describe what is happening.

For example, using 'they/their/them' to mean 'he or she/his or her/him or her' is a common piece of descriptive grammar. For example,

An individual can update their profile with their name and address.

Another grammar point that is becoming more common is using the verb 'graduate' without 'from'. For example,

I graduated Japan university.
I graduated from Japan university. (standard usage)

Descriptive grammar is important to know because it describes how the language is actually being used. However, it is sometimes considered too casual or incorrect by some. It is not appropriate to use this type of grammar for school papers or business documents.

What is Prescriptive Grammar?

Prescriptive grammar is more familar to us. This is the type of grammar that is described in most older textbooks and reference books. If you are an ESL/EFL student you have studied these rules in class and drilled sentences with this grammar. If you are a professional writer you have seen these rules in the style guides such as the AP style guide that are in common use.

Prescriptive grammar is usually the safest type of grammar to use. Professors and teachers expect you to use this type of grammar and publishers will require you to use it. Be sure to check the appriopriate guides for your industry.

Where does Prescriptive Grammar Come From?

About 500 years ago, there weren't any grammar rules for English. The same word had several different spellings. There were different regional dialects of English that had their own structure and vocabulary.

William Bullokar wrote one of the first grammars for English in 1578. He also invented a standard alphabet for the English language. This first grammar book was written like the Latin grammar books written during the 16th century. William wanted English to become a widely used language. It had to be accepted by academics and scholars. So, he created rules similar to rules in Latin. Latin was used by academics and religious scholars at that time and it was highly respected. At the same time, English was seen as a common language used by the people and not highly respected.

Which is better Descriptive Grammar or Prescriptive Grammar?

This is a difficult question. You must think about your audience (the people reading or listening to you). If your audience is academic or you are writing for business, it's better to use prescriptive grammar. In more casual situations, like emails, friendly chats, or (some) blogs, it's perfectly acceptable to use descriptive grammar

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What do you think of prescriptive or descriptive grammar? Let me know in the comments below.