Prescriptive: This is how it should be. In theory. Sentences may not end with prepositions. That word doesn’t mean this. This word isn’t pronounced like that or spelled like that. The work is to be done in such and such a fashion.
Descriptive: This is how it is. In practice. Sentences end with prepositions sometimes. Words’ meanings, pronunciations, and spellings are messy. The job gets done how it gets done.
When you spend a lot of time and energy mastering a complex technical skill, you develop a strong desire to be prescriptive. “I’ve learned how this works. It was hard. You’re doing it wrong.”
It makes sense: You’ve made an investment in learning the rules. Now you want to show people how to follow them.
The rules are there for a reason. They’re usually the sum of many hard-won lessons. We’ve found that things work better when we follow them.
But the rules do change. They change when people break them. People discover ways things can work a little better. One gal tries something just a little different, the next guy notices and follows suit, and so on and so on. One day we wake up and notice that the rules aren’t what they used to be.
It’s great to know the rules, but hold on loosely.
