午前中

1. Origins, structure, and basic meaning

• Structure: 午前中(ごぜんちゅう) refers to the morning period before noon.
• Basic usage: 午前中に places an event or its completion within that period.

2. Common pitfalls and similar expressions

• Within the period, not throughout
  • 午前中に届く means arriving sometime during the morning, not that the act of arriving continues all morning.
• Adding the day
  • 明日の午前中 means tomorrow morning. 午前中 alone does not specify the day; context or a date expression supplies it.