"I'm in the middle of something." - It is important to put quotation marks when you ar quoting something.

This is the sentence which I learned yesterday by while watching an English Lesson TV program.
I was watching this program with my 4-year-old daughter.

This is what I always said say to my daughter, (The comma is important. If the comma is not there, it will look like your daughter's name is LOL) LOL.

"Wait, I'm in the middle of something. I'm tied up"

がんばってください！＾＾

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In Japanese
今、忙しい
昨日のテレビ英会話では、この言い方を習いました。
この番組を4歳の娘と一緒に見ていました。

これはいつも私が娘に言ってることじゃないですか（笑）

「ちょっとまって、今、忙しいの。手が離せないから」