回収

1. Origins, structure, and basic meaning

• Structure: The written form is 回収, read かいしゅう. This noun denotes collecting distributed items or recalling defective products.
• Basic usage: 答案用紙を回収する describes collecting answer sheets after class, while 製品を回収する describes a store recalling a defective product.

2. Common pitfalls and similar expressions

• Answer sheets collected after class
  • Answer sheets are collected at the end of class. Example: 授業の終わりに答案用紙を回収した。 — We collected the answer sheets at the end of class.
• A defective-product recall
  • The store recalls a product because it is defective. Example: 不具合のある製品を店が回収している。 — The store is recalling the defective product.