What is the difference between "投函" and "等閑"?

"投函" means "to post (a letter); to mail (a letter)" (N2), whereas "等閑" represents "neglect; indifference; leaving alone" (N1).

Kanji Homophone Battle

Pronunciation Trap: "とうかん (tōkan)"

Same sound, completely different Kanji! Choose the right conceptual writing.

Kanji Option A

とうかん (tōkan)

N2 / CEFR

Kanji Option B

とうかん (tōkan)

N1 / CEFR

In Japanese, many words share the exact same pronunciation "とうかん (tōkan)" but are written with different Kanji, changing the meaning entirely.

投函 (Level: N2): Translates to "to post (a letter); to mail (a letter)" and is used when Specifically refers to the act of putting a letter, postcard, or other mail into a mailbox.
等閑 (Level: N1): Maps to "neglect; indifference; leaving alone" and carries the nuance of Usually used in the phrase 等閑に付す.

Mixing these up can easily result in unnatural writing. Look at the bilingual context cards below to master the conceptual boundaries!

Bilingual Context for "投函"

書き終わった手紙をポストに投函した。

I posted the letter I had finished writing into the mailbox.

Bilingual Context for "等閑"

重要な問題であるにもかかわらず、彼はその提案を等閑に付した。

Despite being an important issue, he neglected the proposal.

Which Kanji perfectly fits this blank space?

Which Kanji perfectly fits the blank: "書き終わった手紙をポストに＿＿＿した。" (Meaning: "I posted the letter I had finished writing into the mailbox.")

🎉 Correct Answer!

Correct! "投函" is used for "to post (a letter); to mail (a letter)" in the context: "I posted the letter I had finished writing into the mailbox.".