挟む

1. Origins, structure, and basic meaning

• Structure: 挟む（はさむ） is a verb meaning to insert or place something between two surfaces or objects.
• Basic usage: ページにしおりを挟む describes inserting a bookmark; 二つの建物に挟まれた細い道 describes a narrow road situated between two buildings.

2. Common pitfalls and similar expressions

• Inserting something versus being between things
  • In しおりを挟む, the bookmark is the object being inserted. The passive form 建物に挟まれた describes the arrangement of buildings on either side of the road, not an action performed by the buildings.
• The form of a similar verb
  • 挟まる describes something becoming caught or lodged between things. It resembles 挟まれる, the passive of 挟む, so do not read 挟まれた in the second example as the past tense of 挟まる.