片側

1. Origins, structure, and basic meaning

• Structure: 片側 (かたがわ) is a noun for one of two sides, used with limiting particles or to modify another noun.
• Basic usage: 片側だけ通行できる limits usable roadway to one side, while 片側の肩 modifies the one shoulder used to carry a bag.

2. Common pitfalls and similar expressions

• Restriction to one side
  • Both 片側だけ with だけ and 片側の肩ばかり with ばかり highlight one-sided restriction. Neither says that both sides are used in turn.