Learn Hardcore German: Nach einer schweren Klassenarbeit bin ich oft genervt, aber später erleichtert, wenn die Note gut ist. - After a difficult class test I am often annoyed, but later relieved when the grade is good.

Klassenarbeit is feminine (die Klassenarbeit in the nominative).
Feminine dative with the indefinite article is einer.
In the dative singular, the adjective after an article gets -en → schweren.

So the correct form is:

nach einer schweren Klassenarbeit
- nach
  - einer (feminine dative) + schweren (dative adjective ending) + Klassenarbeit

If it were accusative (which it is not with nach), you might see something like eine schwere Klassenarbeit, but nach simply doesn’t use the accusative.

Why is the word order bin ich oft genervt instead of ich bin oft genervt?

German main clauses have a verb-second rule: the conjugated verb must come in the second position in the sentence.

The first position here is taken by the time phrase:

Nach einer schweren Klassenarbeit → position 1
bin (the verb) → position 2
ich oft genervt → the rest of the sentence

So the structure is:

Nach einer schweren Klassenarbeit | bin | ich oft genervt.

If you start with the subject instead, you get:

Ich bin oft genervt nach einer schweren Klassenarbeit.

Both are correct; the sentence just chooses to emphasize the time by putting it first, which then forces bin into second place and pushes ich later.

Does genervt mean “nervous”? How is it different from nervös?

genervt does not mean “nervous”; it usually means:

annoyed
irritated
fed up

nervös is the one that really means “nervous” in English (anxious, jittery).

Examples:

Ich bin genervt. → I’m annoyed / I’m irritated.
Ich bin nervös. → I’m nervous (e.g. before an exam).

So in the sentence:

bin ich oft genervt → “I am often annoyed / stressed out” (by the test),
not “I am often nervous.”

Why is there no bin before später erleichtert? Should it be aber später bin ich erleichtert?

The full, explicit version would indeed be:

Nach einer schweren Klassenarbeit bin ich oft genervt, aber später bin ich erleichtert, wenn die Note gut ist.

However, German allows you to omit repeated verbs in coordinated clauses when the meaning is clear. The bin from the first part is understood to apply to the second part as well:

… bin ich oft genervt, aber (ich bin) später erleichtert …

This is called ellipse (leaving out something that is understood). It is very natural and common in everyday German.

If you prefer a more learner-friendly or very clear style, you can always say aber später bin ich erleichtert.

Why is wenn used here and not wann or falls?

Each of these has a different use:

wenn = when / whenever / if (for repeated or conditional situations)
wann = when? (for questions about time)
falls = if / in case (more clearly conditional, often more hypothetical)

In the sentence:

… später erleichtert, wenn die Note gut ist.

This means: “later I am relieved when(ever) / if the grade is good.”
It describes a general condition that is regularly true, so wenn is correct.

You would use:

wann in a question:
- Weißt du, wann die Note kommt? → Do you know when the grade is coming?
falls for something more like “in case” or “if by any chance”:
- Falls die Note gut ist, feiern wir. → If the grade is good / in case the grade is good, we’ll celebrate.

Why does the verb ist go to the end in wenn die Note gut ist?

Because wenn introduces a subordinate clause (Nebensatz), and in subordinate clauses the conjugated verb goes to the end.

Pattern:

Main clause: verb in second position
- Die Note ist gut. → ist is in 2nd position.
Subordinate clause with wenn: verb at the end
- wenn die Note gut ist → ist is at the end.

So the full structure is:

… bin ich oft genervt, aber später erleichtert, wenn die Note gut ist.
- Main clause: bin in 2nd position
- Subordinate clause: ist at the end

What exactly does Note mean here? Isn’t Note “note” (like on paper or in music)?

Note is a false friend for English speakers.

Common meanings of die Note in German:

grade, mark in school or university
- eine gute Note bekommen → to get a good grade
- This is the meaning in the sentence.
musical note
- die Noten lesen → to read sheet music

If you mean a written note (like a reminder), you usually use:

die Notiz → eine Notiz machen (to make a note)
der Zettel → a slip of paper / little note

So in the sentence, die Note clearly means “the grade”.

Why is oft placed as bin ich oft genervt and not bin ich genervt oft?

German has preferred positions for adverbs in the middle field (the part between the conjugated verb and the sentence-final elements). Adverbs of frequency like oft usually come:

before adjectives and participles used as predicates,
and generally fairly early in the middle field.

So:

bin ich oft genervt sounds natural and is the normal order.
bin ich genervt oft is grammatically possible but sounds unnatural and marked.

Typical pattern:

Ich bin oft müde.
Sie ist manchmal gestresst.
Wir sind selten erleichtert.

So you can remember: frequency adverb (oft, selten, manchmal) normally comes before the adjective like genervt, müde, gestresst.

What is the difference between schwer and schwierig? Could I say nach einer schwierigen Klassenarbeit?

Both schwer and schwierig can mean “difficult,” and often they are interchangeable. However:

schwer literally means “heavy” and by extension “hard / difficult.”
schwierig is “difficult” in the sense of complicated, challenging.

In everyday speech:

eine schwere Klassenarbeit
eine schwierige Klassenarbeit

Both are fine and very common.

If you use schwierig in the dative feminine after nach einer, it declines the same way:

nach einer schwierigen Klassenarbeit

This matches the pattern: dative singular with article einer → adjective ending -en.

What is the difference between Klassenarbeit, Prüfung, and Test?

These words all relate to assessments, but they’re used in slightly different contexts:

die Klassenarbeit
- Typically in school (not university).
- A written test done in class, often longer or more important than a quick quiz.
- Roughly: “class test” or “class exam.”
die Prüfung
- More general word for exam.
- Used for important exams: final exams, driving test (Führerscheinprüfung), official language exams, university exams, etc.
der Test
- Similar to English test, can be written or oral.
- Often a bit more informal or for smaller assessments / quizzes, but also used more broadly.

In the sentence, Klassenarbeit suggests a school written test rather than a big, formal exam like a final Prüfung.