Before Jin's departure on the raft, Sun gave him a notebook that listed several phonetically spelled English words in Korean (at least five words were written on the first page). This was to help Jin communicate with Sawyer and Michael. Sun's actions in preparing the notebook for her husband made him realize how much she still cared for him, and gave him further reason to leave on the raft; Jin wanted to get rescued to save Sun. ("Exodus, Part 1")
The notebook was titled "Korean Dictionary" (영한 사전 Yeonghan Sajeon) on the first page. It was presumably destroyed when the Others blew up the raft.
While on the raft during "Exodus, Part 2", Jin was reading or at least holding the notebook while looking toward the horizon, as if trying to memorize some of the words. The notebook itself seemed to be made from various different pieces of paper encased in a plastic ringed booklet, which seemed to have a latch to open and close it, possibly all fashioned with parts of the Flight 815 wreckage by Sun.
Years later, Sun found herself communicating with a different notebook after temporarily losing the ability to speak English. ("The Package")
Sun gives Jin the notebook in ("Exodus, Part 1").
Confirmed words listed in notebook
- Starboard - First word spoken when the notebook is initially handed to him.
Jin confirmed he knew at least five words from the notebook when Michael asked him what words were in the book:
- Aft (This was on the first page of the notebook.)
These next words were written on the first page of the notebook when Jin first opened it.
- Aft (as above)
Possible words listed in notebook
These were words Jin appeared to know and understand; however, that may be attributed to the initial raft building processes with Michael, as it was stated they were beginning to understand each other.
- Rudder – Began shouting "Rudder!" before anybody else did. Michael mentioned the word rudder before Jin had the notebook when saying, "We need to fix the rudder before we even start to think about that."
- Rope – Appeared to know what rope was, and repeated the word, when Michael asked for it.
- Safe – Asked Sayid in English if it was safe to land on the Pala Ferry in "The Glass Ballerina".