Top 7 German Grammar Mistakes a German Grammar Checker Catches Instantly

7 Grammar Mistakes Every German Grammar Checker Should Catch

Some German grammar mistakes are so common that even native speakers make them daily. Whether you're learning German or writing professionally, these seven errors are the ones most likely to slip into your text. The good news? A quality German grammar checker catches all of them in seconds. Let's look at each mistake, why it happens, and how a German grammar check fixes it.

1. Dativ vs. Akkusativ Confusion

The mistake: Using the wrong case after prepositions and verbs.

• ❌ "Ich lege das Buch auf dem Tisch." (Wrong — movement = Akkusativ)
• ✅ "Ich lege das Buch auf den Tisch." (Correct — Akkusativ for movement)
• ✅ "Das Buch liegt auf dem Tisch." (Correct — Dativ for location)

Why it's tricky: Two-way prepositions (Wechselpräpositionen) like auf, in, an, über take either Dativ or Akkusativ depending on whether the action involves movement or location. A grammar checker for German analyzes the verb to determine which case is correct.

2. Wrong Comma Before "dass"

The mistake: Forgetting the comma before subordinate conjunctions.

• ❌ "Er sagt dass er müde ist."
• ✅ "Er sagt, dass er müde ist."

Why it's tricky: In English, commas before "that" are usually optional. In German, they're mandatory before "dass", "weil", "obwohl", "wenn", and other subordinating conjunctions. A German grammar corrector never misses these.

3. "Seit" vs. "Seid"

The mistake: Confusing the preposition "seit" (since/for) with the verb form "seid" (you are).

• ❌ "Ihr seit gestern nicht da gewesen."
• ✅ "Ihr seid gestern nicht da gewesen." (verb: to be)
• ✅ "Seit gestern bin ich krank." (preposition: since)

Why it's tricky: They sound identical when spoken. Even native speakers make this mistake constantly. A German grammar check online analyzes sentence context to pick the right one.

4. "Das" vs. "Dass"

The mistake: Confusing the article/pronoun "das" with the conjunction "dass".

• ❌ "Ich weiß, das er recht hat."
• ✅ "Ich weiß, dass er recht hat." (conjunction introducing a clause)
• ✅ "Das Buch ist gut." (article for neuter nouns)

Why it's tricky: The rule is simple (replace with "dieses/welches" — if it works, use "das"; if not, use "dass") but people forget under time pressure. A German grammar checker applies this rule perfectly every time.

5. Compound Words Written Separately

The mistake: Writing compound words as two separate words.

• ❌ "Ich muss noch Staub saugen."
• ✅ "Ich muss noch staubsaugen."
• ❌ "Das ist ein Schreib Tisch."
• ✅ "Das ist ein Schreibtisch."

Why it's tricky: Compound words are natural in German, but learners (and even native speakers influenced by English) tend to separate them. A German grammar check tool catches these because its AI understands which word combinations must be written together.

6. Wrong Verb Position in Subordinate Clauses

The mistake: Keeping the verb in position 2 inside subordinate clauses.

• ❌ "..., weil ich bin müde."
• ✅ "..., weil ich müde bin." (verb goes to end)

Why it's tricky: In spoken German, especially in southern dialects, people often put the verb in position 2 after "weil". In written German, this is always wrong. A grammar checker for German enforces the correct subordinate clause word order.

7. Adjective Ending Errors After Articles

The mistake: Using wrong adjective endings based on article type and case.

• ❌ "ein großer Haus" (neuter noun, wrong ending)
• ✅ "ein großes Haus" (neuter + Nominativ + indefinite article = -es)

Why it's tricky: German adjective endings follow three different patterns depending on whether the adjective comes after a definite article, indefinite article, or no article — combined with four cases and three genders. That's 48 possible combinations. No wonder people get it wrong. A German grammar corrector knows all 48 and never hesitates.

How Many of These Does Your Current Tool Catch?

Most generic spell checkers catch at best 2–3 of these seven error types. A dedicated German grammar checker like German Check catches all seven — because it was built specifically for the complexities of German grammar.

Here's a quick comparison:

Run Your German Grammar Check Now

Don't let these common mistakes undermine your German writing. Visit germancheck.de and run a free German grammar check online. Paste your text, see every error highlighted, and read the German explanation for each one. Try the German grammar checker that catches what others miss.