Teachers just assume that you want to speak and write correctly. But it is possible that you don’t care, or even have a desire to speak incorrectly (because it peeves certain people that you may enjoy bedeviling). So, at the outset of this journey, reflect on why it should be important to you to be able to speak and write correctly.
Two Good Reasons:
First, speaking correctly is very similar to having good manners. If you are like most people, you would rather make favorable impressions on others — on strangers, friends and family. If you want to appear educated and smart, it is foolish to use the language of the ignorant, stupid and unschooled. (If you want to appear ignorant, stupid and unschooled, incorrect speech is a very efficient way to achieve it.)
Like good manners, your standards may drop when you are in the familiar surroundings of home or in the good company of friends. That’s normal. The key point is this: It is essential to know how to speak correctly when it matters.
Second, correct speech is, almost by definition, precise, logical, expressive and communicative. If you want to be understood, be clear; if you want to be clear, speak correctly. If you do not care whether you are understood, it would probably be better to be quiet. There is an old adage: “It is better to be quiet and be thought a fool, than to open your mouth and remove all doubt.”
At Least Be Aware
Even when it is not very important to speak correctly, that is, when you could probably get by with a few grammatical errors and rhetorical barbarisms, at least you should be aware of the sort of language you are using, and why. If you “know better,” you will probably be in the habit of speaking correctly, even when it does not matter in any important way. There really is no excuse for saying or doing something that is wrong, even if the consequences are minimal. A person who disagrees with that has a problem that is much more severe than improper English.
Don’t be a Grammar Nazi
In understanding other persons, your main source of information is the language they use, along with their gestures and facial expressions. If you have acquired the habit of always speaking correctly, you will automatically notice when someone else does not. It’s automatic, in the same way that you will notice immediately whether a person is polite or rude, assuming that you already know how to be polite.
But . . . do not correct another person when he or she errs. The only exceptions are (a) if you are the teacher; or (b) if you have been invited by that person to make a correction. Others are free to abuse the English language as they wish. You are free to decide how you feel about it, but you are not free to give unsolicited critiques of another person’s usage. Don’t do it. That is what a “Grammar Nazi” is. Grammar Nazis are not providing a public service by correcting others; they are simply massaging their own egos at the expense of someone else. And all the world hates them. How others express themselves is information for you, but it is information for your private use!