Dear Sir or Madam,
I have been learning English, as a foreign language, for four years until now; yet I have a big problem with using articles. Actually this problem doesn't appear all the time. But it only pops up in some certain positions, especially with the a. In my language, Arabic, it would be very appropriate to add an article in the same position of a sentence which would be inappropriate to use it in a similar position in English. For example: I, as teacher or as a teacher, appreciate the slightest effort a student of mine would exert. Which part is correct: the one with a or the one without it? Another example: I have family/ I have a family.
Help me with this, please.
That is a very good question. Articles are different in every language, and they are often very hard. I have been learning Japanese as a foreign language for several years, and it still confuses me: It has not articles at all!
Here is a website I hope you will find useful. It explains English articles from an Arabic perspective.
There is another way to think about it. This way doesn't always work, but it works enough to be useful. Look at your example: "I have a family." A very long way to say that would be: "There are many families in the world. I have (at least) one of them." Look at your other example: "As a teacher, I appreciate the slightest effort a student of mine would exert." A long way to say that would be: "There are many teachers in the world. As (at least) one of them, I appreciate the slightest effort a student of mine would exert."
This long way of saying things gives you a very good hint about when to use "a" or "an." If this long way makes a good English sentence, you should probably use the indefinite article. Let me finish with just a few other examples.
* George ate a hamburger.
- There are many hamburgers in the world. George ate (at least) one of them.
* Susan gave a bone to the dog.
- There are many bones in the world. There are also many dogs. Susan gave (at least) one of the bones (we don't know which bone) to one particular dog (we do know which dog), so we say "a bone" and "the dog."