補完

1. Origins, structure, and basic meaning

• Structure: 補完 (ほかん) is an action noun, used with する, for making something complete by supplying what is missing.
• Basic usage: 図で補完した uses diagrams as the means of supplying information missing from text, while 技能は補完し合っている describes two skill sets continually filling each other’s gaps.

2. Common pitfalls and similar expressions

• Means marker and reciprocal action
  • 図で marks the means of supplementation, not what receives it. In 補完し合っている, the element 合う makes the relation reciprocal rather than one-sided.