Indefinite Articles

1
Indefinite Articles
Countable Uncountable Noun
2
Uncountable Nouns

• They refer to things that we dont usually think
  of in terms of units.
• That do not have clear shape, form water, rice,
  gravity, magnetism, information, engineering,
  etc.
• Some common types
• A physical mass without definite shape
• An abstract concept
• A continuous process
• A field of study

??? ????
sugar, sand, and gas, etc.
gravity information, etc
photosynthesis, pollution, etc
mathematics, chemistry, business, etc.
3
Countable Nouns - think of in terms of
units

• Nouns represent concepts or objects that do have
  a clear form.
• In plural form
• books, automobiles, molecules
• With numbers
• Four computers
• With quantifiers
• Several books, many microscopes, few molecules

Book, automobile, molecule, computer, and
microscope
4
Indicate the level of generality
a or an ? When you use a singular countable noun
to refer to a general type of
substance, concept, process, etc.
5
Counters

• Using a counter to modify the uncountable nouns
  to be counted.
• You could say
• a cup of rice
• two cups of rice

You would not normally say a rice or two rice
Other common counters are liters of
countable
Notice that the counter is in the plural form
6
Two-Way Nouns

• Many nouns can be refer to either countable or
  uncountable concept, depending on the writers
  focus.
• Ex
• metal
• Knives are usually made by metal.
• Brass is an alloy composed of two metals, zinc
  and copper.

7
Informal Usages

• The situation of hearing spoken but rarely seeing
  in writing.

A student may read aloud this equation as
one copper plus two sulfuric acid(s) yields one
copper sulfate plus one sulfur dioxide plus
two water(s).
More formal reading
One atom of copper plus two molecules of
sulfuric acid, etc.