===== Articles =====
**What it is:** Small words before nouns: **a/an** (indefinite) and **the** (definite).  
**What it’s for:** Show if something is new/any one vs specific/known.  
**Example:** “I bought **a** book. **The** book is interesting.”

===== a / an =====
  * Use for **one** non-specific thing (first time).
  * **a** + consonant sound: a car, a university (/ˌjuːnɪˈvɜːsəti/)
  * **an** + vowel sound: an apple, an hour (/aʊə/)

===== the =====
  * Use when it’s **specific/known**: “the book you gave me”
  * Use with unique things: the sun, the internet
  * Use when both speaker and listener know: “Close the door.”

===== No article (∅) =====
  * Plural/general: “Books are useful.”
  * Uncountable/general: “Water is important.”

===== Hard words (Glossary) =====
  * *article* /ˈɑːtɪkəl/: mạo từ
  * *definite* /ˈdefɪnət/: xác định
  * *indefinite* /ɪnˈdefɪnət/: không xác định
  * *uncountable* /ʌnˈkaʊntəbl/: không đếm được