毎日

1. Origins, structure, and basic meaning

• Structure: 毎日 (まいにち) is a temporal noun used adverbially to express repetition on every day.
• Basic usage: 毎日三十分歩く sets the frequency of walking, while 日記を毎日書く sets the recurrence of a journaling habit.

2. Common pitfalls and similar expressions

• Frequency versus duration of one occurrence
  • 毎日 gives the recurrence, while 三十分 gives the duration of each day’s walk. 毎日三十分 should not be collapsed into one period of thirty days or an entire day.