Forgive me for beginning with an off-topic question but I'll explain why I am doing this later. Did you sleep good last night? Please answer it. Before you go on reading this message think of your answer. Did you sleep good last night?
One teacher told me that she is running into some problems in teaching correct English form for the CET test.
This kind of problem divides the men from the boys (and the women from the girls). Many of us are opposed to teaching grammar rules in our classes as, according to many theories on English teaching, it does not facilitate or even impedes acquisition.
Consequently, there are many of us who are teaching who don't have a strong grasp of all the grammar rules. (I'll put my name on this list.)
We have a tendency to lean on what "sounds right" but then sometimes have a difficulty knowing why something is right (or wrong). Surprisingly, this is often not a problem for the work that native EFL English teachers do as they focus on helping students learn to communicate.
But occasionally there is a time when the teacher has to get into the mechanics of the language and saying "it doesn't sound right but I don't know why" or "there are no rules for English anymore" just doesn't do the job. (Some teachers employ elaborate schemes to avoid having to explain a grammar point or even event some academic gibberish and get off the subject quickly.)
Let's look at driving. You may happily drive your car for years without really understanding how it works. Perhaps you know something is wrong when you hear some odd noise but knowing when your car "sounds" right or wrong is sometimes not sufficient. If you can interpret a distinctive knocking sound coming from the engine whenever you accelerate you can know exactly what is wrong and how to fix it or what mechanic to get to help you. Some people are drivers and some of are driver/mechanics.
Some of these tests revel in the realm of grammar mechanics and are a minefield for teachers who are not well grounded in the mechanics of grammar and usage.
A large percentage of native English speakers use incorrect grammar. This is a vast gray zone. On the one hand a certain way of saying something is incorrect. On the other hand if enough people will use it then it will become accepted.
Let's look at our question at the beginning of the message. For some of you it sounded odd and some of you didn't notice. Some of you knew exactly what was wrong and some only thought it did not sound right.
A lot of Americans think nothing of saying "Did you sleep good?" and it has almost become accepted speech even though "good" is an adjective and "well" is the adverb we need. These kinds of things are in the Twilight Zone of English usage. I think Britons would have little tolerance for such usage but it is no problem for Americans.
The dictionary reminds us here that "[good} should not be used as an adverb with other verbs: The car runs well (not good). Thus, The dress fits well and looks good."
Many people say they speak "good English". They are actually stating that they have chosen one good English over the bad Englishes and they can speak it too. However, we still don't know if they can speak that good English well.
Lots of teachers would like to steer clear of such a job as master mechanic of the English language. But if you find you have such a job then take it as a heaven sent opportunity to dig out those grammar books and get it all straight in your mind.
Although we may not think teaching grammar rules is good pedagogy it does not excuse the teacher from not knowing the rules.