“~n” is to attached at the end of the verb like : (iku) ikun, (kau) kaun. “~n” is used when you want to emphasize something that you WILL do it.

Example
Q: Kobayashi, shopping? - Kobayashi san, kaimono desu ka?
A: Yeah. Are you going for shopping too? - Ee. Toni san mo kaimono ni ikun desu ka?
Q: No, I am going to the library - Iie, watashi wa toshokan e ikun desu
Meaning : Kaimono (Shopping), Toshokan (Library)

Q: What are you doing? - Nani o shite irun desu ka?
A: I am practicing the writing of kanji - Kanji no renshū o shite irun desu
Meaning : Renshū (Practice), Kanji (Chinese Characters)

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