並ぶ

1. Origins, structure, and basic meaning

• Structure: 並ぶ is read ならぶ and describes people or things lining up in a row or sequence.
• Basic usage: It can describe customers forming a queue or bottles remaining arranged on a shelf.

2. Common pitfalls and similar expressions

• Compared with 並べる
  • The short examples 瓶が並ぶ and 瓶を並べる contrast bottles being in a row with someone arranging them. が and を reveal the different roles.
• Conjugation and state
  • The forms are 並ぶ → 並んで → 並んだ. In the example, 並んでいた describes an arrangement that was already in place.