並行

1. Origins, structure, and basic meaning

• Structure: 並行 (へいこう) means proceeding simultaneously or extending side by side. The examples are temporal and spatial.
• Basic usage: Work and study proceed together; two roads run parallel along a river.

2. Common pitfalls and similar expressions

• Concurrent tasks and parallel roads
  • 仕事と勉強を gives temporal concurrency; 道路が gives spatial alignment. The second progressive is a continuing state.