Indefinite Articles Countable & Uncountable Noun

Uncountable Nouns They refer to things that we don ’ t usually think of in terms of units. They refer to things that we don ’ t usually think of in terms of units. That do not have clear shape, form: water, rice, gravity, magnetism, information, engineering, etc. That do not have clear shape, form: water, rice, gravity, magnetism, information, engineering, etc. Some common types Some common types A physical mass without definite shape A physical mass without definite shape An abstract concept An abstract concept A continuous process A continuous process A field of study A field of study 可以用 : 增加說明 sugar, sand, and gas, etc. gravity information, etc photosynthesis, pollution, etc mathematics, chemistry, business, etc.

Countable Nouns - think of in terms of units Nouns represent concepts or objects that do have a clear form. Nouns represent concepts or objects that do have a clear form. In plural form In plural form books, automobiles, molecules books, automobiles, molecules With numbers With numbers Four computers Four computers With quantifiers With quantifiers Several books, many microscopes, few molecules Several books, many microscopes, few molecules Book, automobile, molecule, computer, and microscope

a or an  When you use a singular countable noun to refer to a general type of substance, concept, process, etc. a or an  When you use a singular countable noun to refer to a general type of substance, concept, process, etc. Indicate the level of generality

Counters Using a counter to modify the uncountable nouns to be counted. Using a counter to modify the uncountable nouns to be counted. You could say You could say a cup of rice a cup of rice two cups of rice two cups of rice You would not normally say “ a rice ” or “ two rice ” countable Notice that the counter is in the plural form Other common counters are * liters of

Two-Way Nouns Many nouns can be refer to either countable or uncountable concept, depending on the writer ’ s focus. Many nouns can be refer to either countable or uncountable concept, depending on the writer ’ s focus. Ex Ex metal metal Knives are usually made by metal. Knives are usually made by metal. Brass is an alloy composed of two metals, zinc and copper. Brass is an alloy composed of two metals, zinc and copper.

Informal Usages The situation of hearing spoken but rarely seeing in writing. 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). ” “ One atom of copper plus two molecules of sulfuric acid, etc. : ” More formal reading :