既に

1. Origins, structure, and basic meaning

• Structure: 既に is read as すでに and means “already”.
• Basic usage: It marks a train having already left and tools already placed in a box.

2. Common pitfalls and similar expressions

• 既に出た / 既に入れてある
  • It is an adverb marking completion before a reference time and combines naturally with result states such as 既に出た and 既に入れてある.