===== Passive Voice =====
**What it is:** Focus on the action/result, not the doer.  
**What it’s for:** Formal writing, news, when doer is unknown/unimportant.  
**Example:** “The cake was made (by my mom).”

===== Form =====
  * **be + V3** (change “be” by tense)
  * Present Simple: is/am/are + V3 → “The room is cleaned.”
  * Past Simple: was/were + V3 → “The room was cleaned.”
  * Present Perfect: has/have been + V3 → “The room has been cleaned.”

===== Active → Passive =====
  * Active: “Someone stole my bike.”  
  * Passive: “My bike was stolen.”

===== Hard words (Glossary) =====
  * *passive* /ˈpæsɪv/: bị động
  * *doer* /ˈduːə/: người làm (tác nhân)
  * *formal* /ˈfɔːməl/: trang trọng