beforehand

1. Origins, structure, and basic meaning

• Structure: 予 appears in compounds about thinking or preparing in advance. It is read よ in 予定, 予約, and 予想.
• Basic usage: 予定 means a plan or schedule, 予約 means reserving a place or time in advance, and 予想 means a prediction or expectation.

2. Common pitfalls and similar expressions

• A plan and a reservation
  • 映画を見る予定だ means planning to see a film.
  • Having that plan does not by itself mean that you have already reserved a seat (予約した).
• An expectation and a guarantee
  • 予想より多い means more than expected, showing that an actual result can differ from an expectation.
  • 予想 is not necessarily a fixed schedule guaranteed to happen.
• Studying in advance
  • 予習, read よしゅう, means studying material before it is covered in class.
  • Its timing differs from 復習, which revisits material already learned.