ball

1. Origins, structure, and basic meaning

• Structure: 球 has 11 strokes and concerns balls or spherical forms. It appears in names of celestial bodies and ball-sport actions.
• Basic usage: 地球 is read ちきゅう, and 投球 is read とうきゅう.

2. Common pitfalls and similar expressions

• A celestial body and pitching
  • 地球 names the planet Earth. 地球の環境 means Earth's environment.
  • 投球 is the act of throwing or pitching a ball. 投球フォーム refers to the pitcher's technique or body movement, not the ball's shape.