[asdfasdf1231]

anyone more fluent can explain 林 role on "我林檎食"? (example for 我吃苹果。)

[yorwba]

林檎 is one way to write "apple" in Japanese using kanji, although it's usually written in kana as リンゴ instead. https://jisho.org/search/%E6%9E%97%E6%AA%8E

It's called 偽中国語 for a reason: Japanese speakers may know some obscure kanji for a word, but that doesn't mean they're the same as the hanzi a Mandarin speaker would use.