What do you mean by 'a'?

Answer 1

There are different ways to define 'a'. For examples, 'a' is:

• The first letter of the English alphabet.
• A symbol in algebra formulas such as (a+bx15=)
• A is an 'article' in the English language.

As an article, 'a' denotes one, but not a specific one. The one can be a person or object. For example, there is a difference between saying:

• A boy fell on the playground.
• The boy fell on the playground. (Refers to one specific boy.)
• A boy wearing all black rode his bike past my house and threw an empty can into my yard.
• The boy rode his skateboard in the park. -- note if I said 'a park', it would not be a specific park.

It can be hard to learn the differences between using 'a' and 'the'. The is more specific to one particular person or thing, while 'a' is not specific.

• The boy licked the outside of a strawberry and put it back with the other strawberries. The teacher asked if I knew which strawberry it was, because it would contaminate all the strawberries with germs from his mouth. I said I couldn't tell, it was just a strawberry among many.
• A teacher wearing a winter coat on a hot day was walking with 10 other teachers toward the school. A boy came running by and knocked papers put of the teachers' hands. The teacher with the winter coat yelled, "I need to find a particular paper!" The other teachers told her it was impossible to know which paper that might be until they picked up all the papers and sorted them out again.

Using 'A' allows us to write about a person or thing, even if we cannot more precisely name or identify the person or thing. If we knew a name, we could instead be more precise.