規則的

1. Origins, structure, and basic meaning

• Structure: 規則的 (きそくてき) adds the quality-forming suffix 的 to rule or regularity 規則.
• Basic usage: It describes a routine or arrangement that follows a steady order or interval.

2. Common pitfalls and similar expressions

• Attributive な and adverbial に
  • 規則的な modifies a noun, whereas 規則的に describes how an action or arrangement occurs.