(Note: This is a series of lessons on でしょう／だろう. Here's the first one, andhere's the second one.)
I was flipping through some of my grammar books while preparing for these lessons on でしょう and だろう.

In doing so, I found out that the “Classic でしょう” we’ve been talking about so far was in a completely different section than “Inward でしょう,” which we’ll be talking about today:

Types of でしょう／だろう

1. Classic でしょう
- a. Seeking Agreement (ii.)
- b. Seeking Verification (i.)
- c. Expressing Sympathy (i.)

2. Inward でしょう (iii.)

3. でしょう of Conjecture (iv.)
- a. Weather でしょう
- b. General Conjecture

My book said that “Classic でしょう” is a JLPT N5 grammar topic. And “Inward でしょう” is a JLPT N3 topic.

However, I didn’t see any difference between these two types of でしょう.

The book had the following sentence:

子供ってなんてかわいいんでしょう。
こども　って　なんて　かわいい　ん　でしょう。
Children are so cute.
Literally: “child + って + how + cute + ん + でしょう.”
Note: なんて is “how” as it is used in a phrase like this: “How cute children are!”

To me, this seemed to be just like saying, “Children are so cute, right?”

...which would be the “Classic でしょう (maybe of verification or agreement).”

But the book said that this でしょう didn’t mean “right?” or “don’t you think?”

It said that it meant “how very!”

Huh?

So I went to our in-house Japanese expert: Princess Rei.

She told me a key reason that this sentence about cute children is not the “Classic でしょう” but rather the “Inward でしょう:”

The speaker is talking to himself or herself.

So when do we say it?

To be honest, I haven’t quite figured that out all the way. Probably because I so rarely hear this usage of でしょう (also, why we won’t spend too much time on it).

The reason I hear this so infrequently is that it is typically used to express deep feelings or strong emotions. And, well, most people don’t just go around talking about their deep emotions out loud.

You will, however, see this quite frequently in books, short stories, etc.

So rejoice, book nerds. Today’s your lucky day.

Example:

人生とはなんと素晴らしいのだろう。
じんせい　とは　なんと　すばらしい　の　だろう。
Life is such an amazing thing.
Literally: “life + とは + なんと + amazing + の + だろう.”
Note: A more literal translation would be “How amazing life is.” But I have a slight aversion to these “How ~ !” sentences, as my English students in Japan used them far too often.

Side Note - Using なんて ＆ なんと

Our first example sentence had なんて. Then our second had なんと.

First, what do they mean?

They both mean “how!” or “what!” the way it’s used in sentences like this:
“How beautiful this flower is!”
“What a beautiful flower!”

Second, what’s the difference?

Well, なんて has a much more casual ring to it than なんと, and as a result you are much more likely to hear なんて in spoken Japanese.

More examples, please...

なんて下品な人たちでしょう。
なんて　げひん　な　ひとたち　でしょう。
These people are so vulgar. // What an uncouth bunch of people.
Literally: “なんて + vulgar + people + でしょう”

Note: I’m not too sure about how to translate 下品（げひん）, as it’s a somewhat versatile word. The kanji mean “low-product,” which is interesting. Dictionaries call it “crude、earthy、vulgar、gross、rough-cut、coarse、vulgar、uncouth、common.” It’s not a nice word. In this example, the person saying or thinking this phrase might be at a wedding, commenting (to themselves) about a group of guests that are drunk and being loud and rude during the bride’s father’s speech. Not classy behavior, that. 下品, indeed.

By the way, you are unlikely to see “Inward でしょう” being used with contracted versions like でしょ、っしょ、and だろ. However, it is used with both でしょう and だろう：

なんて下品な人たちだろう。
なんて　げひん　な　ひとたち　だろう。
These people are so vulgar. // What an uncouth bunch of people.
Literally: “なんて + vulgar + people + だろう.”

And one more:

なんて優しい女性だろう。
なんて　やさしい　じょせい　だろう。
What a nice girl.
Literally: “なんて + nice / kind + girl / female + だろう.”

Note: For example, if you saw an old lady fall down outside the station, then you saw a sweet young lady go up to the old lady, help her up, and offer to carry her bags and walk her home, then you might think this sentence to yourself. ( ☚ This really happened by the way. Rei walked an old lady home after she fell, and the old lady gave her chocolate as a way of saying thank you. Then I ate the chocolate when Rei brought it home! ^_^)

なんて優しい女性でしょう。
なんて　やさしい　じょせい　でしょう。
What a nice girl.
Literally: “なんて + nice / kind + girl / female + でしょう.”

Hang on: I'm confused.

Knowing nuances and meanings is cool and all, but how exactly do we use でしょう and だろう？

That is, what types of words can they attach to?

Well pretty much anything... except ます-verbs and て-form verbs.

So if we take all these types of words...

Noun
医者（いしゃ / doctor）
医者だった（いしゃ　だった / was a doctor）

Na-Adjective
元気（げんき / healthy; well; lively）
元気だった（げんき　だった / was healthy; was well; was lively）

i-Adjective
美味しい（おいしい / delicious; tasty）
美味しかった（おいしかった / was delicious; was tasty）

Verb
食べる（たべる / eat）
食べない（たべない / don't eat）

食べます（たべます / eat）
食べません（たべません / don't eat）

Past-Tense Verb
食べた（たべた / ate）
食べなかった（たべなかった / didn't eat）

食べました（たべました / ate）
食べませんでした（たべませんでした / didn't eat）

て-form Verb
食べて（たべて / eat and...）

...then that would mean that でしょう and だろう can（〇） or cannot（✖） attach to...

〇　医者でしょう
〇　医者だったでしょう
〇　元気でしょう
〇　元気だったでしょう
〇　美味しいでしょう
〇　美味しかったでしょう
〇　食べるでしょう
〇　食べないでしょう
✖　食べますでしょう
✖　食べませんでしょう
〇　食べたでしょう
〇　食べなかったでしょう
✖　食べましたでしょう
✖　食べませんでしたでしょう
✖　食べてでしょう

How am I supposed to remember all of that?!

Don't.

Just get a feel for it naturally over time.

Unless you're in a Japanese language class, I guess. I hear they have tests *_*.

Lesson Complete!

Tomorrow we’re going to take a short detour from でしょう so that we can look at a little piece of grammar just like the one we explored today... only it shows up in JLPT N2!

Bonus Phrases

父は昔、医者だった。
ちち　は　むかし、　いしゃ　だった。
My dad used to be a doctor (a long time ago).

久しぶり！元気だった？
ひさしぶり！　げんき　だった？
Long time no see! How have you been?

あ～美味しかった！
あ～　おいしかった！
Ah... that was delicious!

今朝は何も食べなかった。
けさ　は　なにも　たべなかった。
I didn't eat anything this morning.