After having authored thousands of printed pages and having taught writing at the graduate level, all in English (my third language), I’ve come to this conclusion: We non-native speakers have a major advantage over native speakers when it comes to writing in the English language. We may not know how to write properly, but at least we know that we don’t know. Most native English speakers don’t know how to write properly either, but they don’t know that they don’t know. Because we’re acutely aware of our language deficiencies, we non-native speakers will generally put much more effort into learning proper English than native speakers will.
However, I’ve often seen non-native speakers worry about grammatical subtleties that no (untrained) native speaker could discern while at the same time making mistakes that no native speaker would ever make. This can lead to the curious situation where a non-native speaker may actually have a pretty good command of the English grammar and yet his writing will be considered as “poor” and “full of errors.” I’ve thus concluded that it may not matter so much that we truly understand English grammar in all its subtleties . What matters most is that we don’t make the mistakes native English speakers wouldn’t make. We can use dangling participles, missing antecedents, and comma splices all day long, and most people won’t hold it against us. But make one non-native mistake, such as not using article when article is needed, and you’ll immediately sound like person with poor English skills.
For example, consider the following atrocity of a sentence:
As a native speaker, writing grammatically correct sentences is difficult for me.
Most native speakers would happily accept this sentence as correct, even though it has a glaring grammatical error . Now consider this sentence:
As non-native speaker, I can write difficult sentence with only few minor errors.
Most native speakers would recoil in horror, yet all the second author is guilty of is omission of a few articles. Fix the articles, and the sentence is perfectly fine:
As a non-native speaker, I can write a difficult sentence with only a few minor errors.
This simple example shows how important it is that you master proper use of articles. In particular, if you’re from Eastern Europe or from Asia and your mother tongue doesn’t have the concept of articles, you will have to put in some serious effort into understanding articles. Otherwise, your prose will always sound like it was written by a foreigner, regardless of how grammatically correct everything else is. So let me give you a brief primer on proper use of articles in the English language.
Definite vs indefinite articles
The definite article, which in English is “the”, refers to a particular member of a group. For example:
The cat is on the roof.
I have to feed the dogs.
The author is talking about one specific cat, one specific roof, one specific dog. By contrast, the indefinite article, which in English can be “a,” “an,” or no article, refers to any member of a group. For example:
A cat is a fierce predator.
An elephant eats foliage.
Dogs give us unconditional love.
The author is now talking about any possible cat, any possible predator, any possible elephant, and any possible dogs. Note that the words “foliage” and “unconditional love” fall under the rule of “things that can’t be counted,” which I’ll discuss in the next subsection.
One thing that may be confusing is that in two subsequent sentences, the same word may need an indefinite and a definite article. For example:
Yesterday, I saw a black cat. The cat crossed the street from left to right.
The first occurrence of the cat requires “a,” because we haven’t heard about the cat before. Thus, at this point in the story, we can only be talking about any arbitrary cat. By the second sentence, though, the cat has been defined. It’s the one that is black and that I saw. Hence, now I have to refer to it as “the cat.” Similarly, I wrote “the cat” throughout this paragraph because I kept referring to that same, black cat defined in the first sentence of the example.
If your native language doesn’t distinguish between definite and indefinite articles it may be difficult for you to get an intuitive sense of what it means to be talking about a specific member of a group or about any arbitrary member of a group. If you experience this problem, you will have to practice deliberately. Don’t think that you’ll just intuitively get it one day, because you won’t. You will have to analyze properly written sentences and for every noun in every sentence figure out exactly why it has the article it does. Then, in your own writing, you will have to go over every noun and determine whether it represents a specific member of a group or any arbitrary member of a group.
Names, countries, things that can’t be counted
Names, countries, and things that can’t be counted generally don't have articles. For example:
Martin likes ice cream.
England borders Europe.
“Martin” is a name, “ice cream” cannot be counted, and “England” and “Europe” are countries. However, don’t get confused by country names that include an article, such as “The Netherlands.” The article is part of the name because the name originally referred to a geographic location, such as “the Alps” or “the Sierra Nevada.”
Places with distinct sets of social behaviors
Finally, here comes my favorite rule about articles. This rule is so awesome it needs to be printed in italics:
We don’t use articles in preprositional phrases referring to places that require a distinct set of social behaviors.
This is such a mouthful, most people cannot even repeat it without error. Yet we all use it instinctively, when we say things like:
Where do you go to school?
Hannah goes to college.
I’ll see you in court.
Here, “school,” “college,” and “court” are all places that require a distinct set of social behaviors. When you want to refer to the specific building, you might say “the school down the road,” but when you want to refer to the social construct of “school” you would always say that you “go to school down the road.”
If you’re a non-native speaker and your mother tongue doesn’t use articles, you'll almost certainly have difficulty with using articles properly. Invest some time and energy into getting articles right, because incorrect or missing articles will make your writing stick out like a sore thumb. Any native speaker will immediately notice issues with articles and will conclude that the text she’s reading is written poorly. (Even if, by absolute standards of grammatical correctness, that’s not the case.)
I'd also recommend that you, if you have any issues with articles, always do a proof-reading step dedicated specifically to articles. Read your entire document from cover to cover and verify that every single noun has whatever article it may need. It’s generally a good habit to do multiple proof-reading passes. Each pass should check for one specific mistake you tend to make. Just add that one more pass and check for articles. When following this recommendation, I expect that you'll write documents in which all articles are right all the time.
 Of course, I’d still recommend that you write sentences that are largely free of grammatical errors. Just aim first for eliminating errors native speakers wouldn’t make. Then eliminate the errors that native speakers make all the time.
 If you don’t know what the error is you’re just demonstrating my point.