減らす

1. Origins, structure, and basic meaning

• Structure: 減らす(へらす) is a transitive verb meaning to make an amount or number smaller.
• Basic usage: In 荷物を減らす, the thing reduced is marked with を.

2. Common pitfalls and similar expressions

• A decrease and an action
  • 荷物が減る describes the baggage decreasing; 荷物を減らす describes the action of reducing it.
• Conditional form
  • The conditional 減らせば means 'if one reduces it'; 減らす changes its final す to せば.