low

1. Origins, structure, and basic meaning

• Structure: 低 expresses a low height or level; 低い is read ひくい.
• Basic usage: 低下(ていか) describes a decrease from an earlier temperature, efficiency level, or similar measure.

2. Common pitfalls and similar expressions

• State and change
  • 低い describes a low state, while 低下する describes a decrease. Being low now and becoming lower than before are different claims.
• Modifier forms
  • 低い椅子 means a low chair, and 低くする means to make something lower. Use い before a noun and く to modify an action.