Learn Hardcore German: Dass die Ernte dieses Jahr so gut war, freut den Bauern sehr. - That the harvest was so good this year pleases the farmer very much.

The subject is the whole dass-clause:
Dass die Ernte dieses Jahr so gut war
(That the harvest was so good this year)
The verb of the main clause is freut (pleases / makes happy).
The direct object (accusative) is den Bauern (the farmer).

So grammatically:

Subject: Dass die Ernte dieses Jahr so gut war
Verb: freut
Direct object: den Bauern

Why does the sentence start with Dass …? Could it also start differently?

Starting with a dass-clause is a way to put emphasis on that whole idea:

Dass die Ernte dieses Jahr so gut war, freut den Bauern sehr.
Literally: That the harvest was so good this year pleases the farmer a lot.

More neutral and very common would be:

Es freut den Bauern sehr, dass die Ernte dieses Jahr so gut war.
It pleases the farmer a lot that the harvest was so good this year.

Here es is a “dummy” subject, and the dass-clause is moved to the end.
Both versions are correct; they differ mainly in style and emphasis, not in basic meaning.

What is the difference between dass and das?

They look similar but have different functions:

dass (with double s) is a subordinating conjunction.
It introduces a subordinate clause (a dass-clause) and does not have gender or number.
Example: dass die Ernte … so gut war
das (with one s) can be:
- the neuter definite article: das Haus (the house)
- a demonstrative pronoun: Das ist gut. (That is good.)
- a relative pronoun: Das Buch, das ich lese … (The book that I’m reading…)

In your sentence, you must use dass because you are introducing a content clause:
Dass die Ernte dieses Jahr so gut war = That the harvest was so good this year.

Why is the verb war at the very end of dass die Ernte dieses Jahr so gut war?

Because dass introduces a subordinate clause, and in standard German subordinate clauses the finite verb goes to the end.

Pattern:

Main clause: verb in 2nd position
Die Ernte war dieses Jahr so gut.
(The harvest was so good this year.)
Subordinate clause with dass: verb at the end
…, dass die Ernte dieses Jahr so gut war.

So:

dass → marks a subordinate clause
therefore war is sent to the final position of that clause.

Why is freut in the second position even though the sentence begins with a whole clause?

German main clauses follow the Verb-second (V2) rule: the finite verb must be in 2nd position in terms of elements, not necessarily single words.

In this sentence, the elements are:

Dass die Ernte dieses Jahr so gut war → counts as one element (a whole clause in the “prefield”)
freut → the finite verb (must be 2nd element)
den Bauern sehr → rest of the main clause

So the main clause structure is:

[1st field] Dass die Ernte dieses Jahr so gut war,
[2nd field – verb] freut
[rest] den Bauern sehr.

Even though that first element is long, it still counts as one “slot” before the verb.

Why is it den Bauern and not dem Bauern?

Because the verb jemanden freuen (to please someone / to make someone happy) takes a direct object in the accusative, not in the dative.

den Bauern = accusative singular masculine of der Bauer
- nominative: der Bauer (the farmer – as subject)
- accusative: den Bauern (the farmer – as direct object)

Examples:

Die Nachricht freut den Bauern.
The news pleases the farmer. (accusative object)
Dass die Ernte so gut war, freut den Bauern sehr.

If you wanted dative, you’d need a different verb pattern like jemandem gefallen:

Die Ernte gefällt dem Bauern.
The harvest pleases the farmer. (dative)

So here freuen → accusative → den Bauern, not dem Bauern.

Is den Bauern singular or plural here?

Formally, den Bauern could be:

accusative singular: den Bauern (one farmer, as object)
dative plural: den Bauern (to/for the farmers)

In this sentence:

The case is accusative, because of the verb freuen (jemanden freuen).
So the most natural reading is accusative singular: the farmer.

If we tried to read it as dative plural, we’d need a verb that takes a dative object like gefallen:

Dass die Ernte dieses Jahr so gut war, gefällt den Bauern sehr.
→ Here den Bauern would be dative plural (pleases the farmers a lot).

But with freut, we interpret den Bauern as accusative singular.

Could I also say Es freut den Bauern sehr, dass die Ernte dieses Jahr so gut war? Is there a difference?

Yes, that is a very natural and common variant:

Es freut den Bauern sehr, dass die Ernte dieses Jahr so gut war.

Difference:

Dass die Ernte dieses Jahr so gut war, freut den Bauern sehr.
→ Focus/emphasis at the beginning on the fact that the harvest was so good.
Es freut den Bauern sehr, dass die Ernte dieses Jahr so gut war.
→ More neutral word order; the dass-clause comes at the end, after a “dummy” es.

Grammatically, both are correct; the main difference is stylistic emphasis.

Why is there a comma after war?

The comma marks the boundary between a subordinate clause and the main clause.

Subordinate clause introduced by dass:
Dass die Ernte dieses Jahr so gut war,
Main clause:
freut den Bauern sehr.

German punctuation rules require a comma:

before or after most subordinate clauses (including dass-clauses)
and between the subordinate clause and the following main clause.

So the comma is mandatory here.

What is the gender and case of die Ernte?

Ernte is:

grammatical gender: feminine
basic form (nominative singular): die Ernte (the harvest)

In the dass-clause, die Ernte is the subject of war:

dass die Ernte dieses Jahr so gut war
→ that the harvest was so good this year

So:

gender: feminine
number: singular
case: nominative (subject of war)

What is the difference between so gut and sehr gut here?

Both express a high degree of “good,” but with a slightly different nuance:

so gut = so good; often suggests comparison, measure, or consequence.
- It can sound like: so good (to such an extent).
- Often used with a consequence clause, e.g. …, dass es den Bauern sehr freut.
sehr gut = very good, simply a high degree, more neutral.

In this exact sentence:

Dass die Ernte dieses Jahr so gut war, freut den Bauern sehr.
→ That the harvest was so good this year makes the farmer very happy.
You might imagine: “so unusually good.”

You could also say:

Dass die Ernte dieses Jahr sehr gut war, freut den Bauern sehr.
→ Also correct, just a bit more neutral (very good, not necessarily with that “to such an extent” flavor).

Why is the tense war (simple past) and not ist (present)?

Ernte (harvest) is typically a completed event in the past — once the harvest is done, you talk about how good it was.

war = simple past of sein (was) → refers to a situation that is already finished.

If the harvest is already over, Germans naturally say:

Die Ernte war dieses Jahr sehr gut.
The harvest was very good this year.

Using ist would sound like the harvest is somehow an ongoing state, which is unusual in this context. So war fits the real-world timing better.

Could I also say Die Ernte war dieses Jahr so gut, dass es den Bauern sehr freut? Would that mean the same?

This sentence is correct but the structure and nuance are different:

Dass die Ernte dieses Jahr so gut war, freut den Bauern sehr.
→ The fact that the harvest was so good this year makes the farmer happy.
(The dass-clause is the subject.)
Die Ernte war dieses Jahr so gut, dass es den Bauern sehr freut.
→ The harvest was so good this year that it makes the farmer very happy.
(Here so … dass expresses degree + consequence: so X that Y.)

So:

First sentence: emphasizes the fact as a whole.
Second sentence: emphasizes how good the harvest was, and then introduces the result.

Both are acceptable, but they are different constructions and highlight different aspects.