Occupation (Articles: a, an, the)

“What do you do?” or “What does he/she do?” is a popular way to ask about someone’s occupation.  What they want to know is what job it is that we hold.
Possible Answers:
I work in a bank. He/She works in a bank.
I’m a banker. He/She is a banker.
I’m in banking.    He/She is in banking.
Wrong:    
- I do banking. *You don’t need to repeat the word ‘do’.*
- I’m watching a movie.  *It’s not asking what activity you are doing presently.*    

To state what we do, what our job is, we always use the articles ‘a’, ‘an’, ‘the’.  
Examples: I am a doctor. He is an engineer. She is a teacher.
This is one of the most general use of articles in the English language.

When we care or want to be specific as to which noun we are referring to, we use the article ‘the’.  This is called the ‘definite’ article.  We also use ‘the’ with a noun when the noun is being mentioned again, to refer back to it.  Definite articles can be used with both singular and plural nouns.
Examples:
- Please bring back the homework tomorrow. (referring to the specific work that has been assigned, not just any work)
- I see a pen.  The pen is black.(referring to the pen that I see–not just any pen)
- The applicants are all waiting to be interviewed. (referring to only those applicants who got called for an interview)

We can also use articles before adjectives when they are introducing/describing a noun.
Examples:
- I need a long skirt for the show. (any long skirt will do)
- Did you see the amazing view on the way here? (referring to only one amazing view–the one we passed along the way)

When we are referring to a noun in general, we use the plural forms without any articles.
Examples:
- I love dogs. (all dogs in general)
- Entrepreneurs need to have a good instinct. (true for all entrepreneurs in general)