掛かる

1. Origins, structure, and basic meaning

• Structure: 掛かる (かかる) is an intransitive verb for time being required or for an object hanging in place.
• Basic usage: It describes travel taking time and a clock hanging on a wall.
  • 駅まで歩くと二十分掛かる。 — It takes twenty minutes to walk to the station.
  • 壁に大きな時計が掛かっている。 — A large clock hangs on the wall.

2. Common pitfalls and similar expressions

• Taking time and hanging
  • In 二十分掛かる it means that time is required; in 壁に掛かっている it means hanging in place. 掛ける is the transitive verb for someone hanging an object.