子犬

1. Origins, structure, and basic meaning

• Structure: 子犬 (こいぬ) is a compound noun for a young dog that has not yet matured.
• Basic usage: 白い子犬が走る makes a puppy the moving subject in a park, while 保護した子犬に水を与える makes the rescued puppy the recipient of water and food.

2. Common pitfalls and similar expressions

• Acting subject and recipient
  • 子犬が is the active subject running on its own, whereas 子犬に is the recipient of something given by people. The relative clause identifies the puppy in the second example as rescued.