Learn Hardcore German: Ich finde das Deutsch in dem Buch leicht.

Deutsch (without article) usually means the German language in general:
- Ich finde Deutsch leicht. – I think German (as a language) is easy.
das Deutsch (with article) often refers to a particular kind or use of German, e.g.:
- das Deutsch in dem Buch – the German in that book, the way German is used/written there
- sein Deutsch – his German (his level / way of speaking)

So:

Ich finde Deutsch leicht. → I find German (in general) easy.
Ich finde das Deutsch in dem Buch leicht. → I find the German used in the book easy.

Why is it das Deutsch (neuter) and not die Deutsch or something else?

In German, Deutsch as a noun meaning the German language is neuter, so it takes das in the singular:

das Deutsch – the German (language or style)
Ich lerne Deutsch. – I am learning German. (no article, but if you add one, it’s das)

You just have to memorize that Deutsch (the language) is neuter.
Compare:

die Sprache (the language) – feminine
die deutsche Sprache – the German language (feminine because Sprache is feminine)
das Deutsch – German (as a language), neuter

Why is it in dem Buch and not something else? Why is dem used here?

The preposition in can take either dative or accusative, depending on whether it means location (where?) or direction (into where?).

Here we are talking about location:

The German in the book (where is it? in the book) → dative

Buch is neuter:

nominative: das Buch
dative: dem Buch

So we get:

in dem Buch = in the book (dative, neuter)

If it were direction, you’d use accusative:

Ich lege das Buch in den Rucksack. – I put the book into the backpack. (movement → accusative)

Can I say im Buch instead of in dem Buch?

Yes. im is simply the contracted form of in dem.

in dem Buch = im Buch

Both are grammatically correct. im Buch is more common in everyday speech and writing:

Ich finde das Deutsch im Buch leicht.

So you can safely use im here.

Why is leicht at the end of the sentence? In English we say “I find the German in the book easy”, with easy earlier.

German word order is different from English. A simple rule:

In a main clause, the conjugated verb (here finde) is in second position.
Most other things (objects, adverbs, adjectives that belong to the verb phrase) come after that, and predicative adjectives (like leicht) usually come towards the end.

Structure of the sentence:

Ich – subject
finde – finite verb (2nd position)
das Deutsch – direct object
in dem Buch – prepositional phrase (where?)
leicht – predicative adjective (how do I find it? easy)

So:

Ich finde das Deutsch in dem Buch leicht.

Putting leicht earlier, like Ich finde das Deutsch leicht in dem Buch, sounds wrong or at least very odd.

Is leicht here “light” (not heavy) or “easy”?

Here leicht means easy, not light in the physical sense.

leicht can mean both, depending on context:

Der Koffer ist leicht. – The suitcase is light (not heavy).
Die Aufgabe ist leicht. – The exercise is easy.

With something like das Deutsch in dem Buch, the natural reading is easy:

Ich finde das Deutsch in dem Buch leicht.
→ I think the German in the book is easy.

What is the difference between leicht and einfach? Could I say einfach instead?

Both leicht and einfach can mean easy, and both are possible here:

Ich finde das Deutsch in dem Buch leicht.
Ich finde das Deutsch in dem Buch einfach.

Nuance:

leicht often focuses on the degree of difficulty: not difficult, easy to handle.
einfach can mean simple, not complicated, and often has an extra nuance of simplicity/straightforwardness.

In many contexts (especially about tasks, language, exercises), they overlap strongly, and both are fine. In your sentence, most native speakers wouldn’t feel a big difference.

Why is das Deutsch accusative here? How can I tell?

In Ich finde das Deutsch in dem Buch leicht, the verb finden has a direct object: das Deutsch. Direct objects in German are normally in the accusative case.

For a neuter noun like Deutsch, nominative and accusative look the same (das):

nominative: das Deutsch
accusative: das Deutsch

So even though the form doesn’t change, das Deutsch here is accusative, because it is:

what you find → Ich finde [was?] das Deutsch in dem Buch.

By contrast:

in dem Buch is dative because of the preposition in
- location (where?).

Can I leave out das and say Ich finde Deutsch in dem Buch leicht?

You can say it, but it sounds odd and unclear. Without das, it sounds like:

“I find German in the book easy,”
which might be misinterpreted as if you discover German in the book or something like that.

Using das Deutsch in dem Buch makes it clear that you are talking about the specific German used in that book (its wording, style, level).

So for the intended meaning, Ich finde das Deutsch in dem Buch leicht (or im Buch) is the natural choice.

Could I change the word order and say In dem Buch finde ich das Deutsch leicht?

Yes. This is perfectly correct and quite natural:

In dem Buch finde ich das Deutsch leicht.

German allows you to move elements (like in dem Buch) to the beginning for emphasis or style. The rule is:

One element in the first position (here: In dem Buch)
The conjugated verb still has to be in second position (here: finde)
The rest follows:
- In dem Buch – first element
- finde – finite verb (2nd position)
- ich das Deutsch leicht – rest of the sentence

Meaning stays the same; the emphasis shifts slightly to in dem Buch.

How would I say this with dass, like “I find that the German in the book is easy”?

You can make a dass-clause:

Ich finde, dass das Deutsch in dem Buch leicht ist.

Here:

Main clause: Ich finde, … – I find / I think …
Subordinate clause: dass das Deutsch in dem Buch leicht ist.

Note the word order in the dass-clause:

ist (the finite verb) goes to the end:
- … dass das Deutsch in dem Buch leicht ist.

Meaning is essentially the same as your original sentence; using dass just makes the “that…” structure explicit.