"I put the postcard in the mailbox."

Translation: ポストにハガキを入れました。

[Rso17]

Why is ハガキ written in katakana?

[ieatpasta]

Why does ”i already put the letter in the mail box" use は and "i put the postcard in the mailbox" use を?

[AmnesicSorcerer]

Does anyone know if there's a reason it should be wrong if one wrote it "ハガキをポストに入れました"?

[LordOfTheAndain]

It is accepted now (sep 2020).

[AdamScott794079]

Is this a postbox or a letterbox?

[sora_Japan]

Perhaps, I think 'ポスト' is a postbox.

Because a letterbox is called '郵便受け'. ポストare in town. 郵便受けare in front of each house.

[Lord_William747]

This question directly contradicts the one before it "あの封筒はポストに入りました" that one i originally got wrong for using を instead of は and now this one i get wrong for the opposite reason. What is the deal??

[Lord_William747]

I mean 入れました