IV. The articles: a, an, the
* “a”:          -  is used before a countable singular noun
- is used to mean “any, every”
* “an”:        - is used instead of “a” before a noun beginning with a vowel sound.
* “the”:       - is used before a noun that has already been mentioned or is easily           understood.
                   - is used to refer to a noun that is the only, or obvious one of their kind.
                    - is used before superlative comparison of adjectives and adverbs
* whether we use “a” or “an” depends on the sound, not the spelling: an hour, a uniform
Practice:
Exercise 1. Fill in the blanks with “a, an, the, any”
1. Do you live in ___________ apartment in town?
    No, we live in ___________ house in ___________ country.
2. There aren’t ___________ restaurants on my street.
3. Is there ___________ vegetable garden in front of ___________ yard?
4. What’s that on the floor? - It’s ___________ eraser.
5. Are there ___________ lakes in your city?
6. Near ___________ river, there is ___________ rice paddy field.
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