二股

1. Origins, structure, and basic meaning

• Structure: 二股(ふたまた) combines 二(ふた), two, with 股(また), a fork or branch.
• Basic usage: It describes a shape that branches in two and also appears in the context of two-timing in a relationship.

2. Common pitfalls and similar expressions

• に分かれる and をかける
  • 二股に分かれる uses に for the resulting division into two branches. 二股をかける in the relationship example is an idiomatic expression; changing its particle does not preserve the same construction.