That thing they call "conversation" is hard, yeah?

You go to lunch with a friend that you haven't seen in ages, and you're supposed to, uh, talk... about stuff.

And stuff.

Luckily, you can hide behind the menu for a while.

Then, pro conversationalist that you are, you might peak over the top of it and ask...

頼むもの決めた？
たのむ　もの　きめた？
Have you decided what you're gonna order?
Literally: "request / order + thing + decided?"
Note: Notice how we can (sometimes) use simple past tense in Japanese (=決めた) for present perfect in English (=have decided).

Your less decisive counterpart may then reply...

ん〜、まだ考え中。
ん～、 まだ　かんがえちゅう。
Hmm... I'm still thinking about it.
Literally: "Hmm..., + still + thought-middle."

Suddenly, Lesson Topic

考える (かんがえる) means "to think."

考え (かんがえ), without the る, is a noun meaning "thought; idea."

Then we have the word 中 (なか), which means "inside; within; in."

Only, we use one of its other readings: ちゅう.

考え＋中
かんがえ＋ちゅう
thought + within / inside
↓　↓　↓
考え中
かんがえちゅう
(be) thinking about (something) // in the middle of thinking

You might be tempted to conclude, from this example, that ～中 (ちゅう) attaches to the stems of verbs or something. Nope, nope, nope.

～中 (ちゅう) doesn't like verbs. It only goes for nouns.

And when it attaches to a noun, it gives off the meaning of "in the middle of NOUN(-ing)."

And the examples... will set you free...

いま運転中だから後でかけ直すね！
いま　うんてんちゅう　だから　あとで　かけなおす　ね！
I'm driving right now, so I'll call you back later, OK?
Literally: "now + driving-middle + だ + because + later + call back + ね!"

デート中は携帯いじらないようにしてる。
デートちゅう　は　けいたい　いじらない　ように　してる。
I try not to mess with my phone when I'm on a date.
Literally: "date-middle + は + mobile phone + don't mess with + am trying to do."
Note: [VERB]～ようにしてる means "am trying to VERB. I'm pretty sure we've seen this before, but maybe we should have a lesson about it in the near-ish future.

仕事中に倒れて病院に運ばれた。
しごとちゅう　に　たおれて　びょういん　に　はこばれた。
I passed out while working, and I was taken to the hospital.
Literally: "work-middle + に + collapse (and) + hospital + に + was carried."
Note: The nuance with 運ばれた is that the speaker was taken to the hospital by ambulance.

散歩中に野生のリスを見つけた。
さんぽちゅう　に　やせい　の　リス　を　みつけた。
I saw [found] a (wild) squirrel while on my walk.
Literally: "walk-middle + に + wild + の + squirrel + を + found."

On a side note, while you're less likely to use the following words in person, it is quite common to see them on signs outside of shops and restaurants...

準備中、商い中、営業中
じゅんびちゅう、 あきないちゅう、 えいぎょうちゅう
Not yet open (for business); Open for business; Open for business
Literally: "preparation-middle, + trading-middle, + business-middle."
Note: We looked at 準備中 and 営業中 way back in Lesson #2! Oh, also, 商い中 and 営業中 have pretty much the same meaning, but I've only seen 商い中 at more traditional Japanese restaurants that serves foods like 和食 (わしょく //[traditional] Japanese [home] cooking), ラーメン (ramen), etc.

That was short and the point, yeah?

Which is to say, you have very few excuses for not going back over this lesson and actually reading each Japanese word. I know that the temptation to skim is difficult to resist. But I have faith in your abilities. You have greatness in you.