留学

1. Origins, structure, and basic meaning

• Structure: 留学 (りゅうがく) means studying at an institution abroad or away from home. The examples use a verb and compound 海外留学.
• Basic usage: A sister studies abroad for one year; documents required for overseas study are prepared early.

2. Common pitfalls and similar expressions

• Completed year abroad and paperwork before departure
  • The first is an actual completed experience; the second is preparation before leaving. 海外 explicitly narrows the destination outside the country.