It's possible you're referring to:
1. Articles "a" and "an": These are definite articles used before singular countable nouns.
* "A" is used before words starting with a consonant sound. For example: "a cat", "a book", "a university".
* "An" is used before words starting with a vowel sound. For example: "an apple", "an hour", "an umbrella".
Importance of articles "a" and "an":
* Specificity: They signal whether the noun is specific or general. "A cat" refers to any cat, while "the cat" refers to a specific cat already known.
* Countability: They are used before countable nouns, indicating that there is one of something.
* Grammar: They are essential for grammatical correctness in English sentences.
2. Articles in speech versus writing:
The way articles are used in speech can differ slightly from written English, particularly in casual conversation. Sometimes, articles might be omitted or used differently.
For example:
* Written: "I bought a new car."
* Spoken: "I bought new car."
In spoken English, the focus is on clarity and natural flow. Articles might be omitted for brevity or emphasis.
If you're unsure about something specific related to articles, please clarify your question with more context.