Learn Hardcore German: Mein Schwiegervater erzählt, wie er vor einem Jahrzehnt seine Karriere in einer kleinen Firma begonnen hat. - My father-in-law tells how he started his career in a small company a decade ago.

In German, you normally use a possessive determiner (like mein, dein, sein, ihr) with family-member nouns, because you usually mean my/your/his/her etc.

Mein Schwiegervater = my father‑in‑law
Schwiegervater alone sounds more like you’re talking about a generic father‑in‑law, or using it as a label (headline, dictionary entry, etc.), not a specific one.

So in everyday sentences about your own relatives, you almost always say mein Vater, meine Mutter, mein Schwiegervater, etc.

What exactly does Schwiegervater mean, and how is it formed?

Schwiegervater means father‑in‑law.

It’s a compound:

schwieger- is a bound form related to in‑law relationships,
Vater = father.

Similarly:

Schwiegermutter = mother‑in‑law
Schwiegersohn = son‑in‑law
Schwiegertochter = daughter‑in‑law

Schwiegervater is masculine:

nominative singular: der Schwiegervater
here we have mein Schwiegervater (nominative, subject of the sentence).

Why is it erzählt and not sagt? What’s the difference?

Both erzählen and sagen can be translated as to say, but they’re used differently:

erzählen = to tell, to narrate
- Often used for stories, experiences, longer or more detailed accounts.
- E.g. Er erzählt von seiner Kindheit. – He tells (talks) about his childhood.
sagen = to say
- More neutral and shorter; often used with direct speech:
- Er sagt: „Ich bin müde.“ – He says, “I’m tired.”

In your sentence, erzählt fits well because he is narrating how his career started – that’s more like telling a story than just saying a short sentence.

What does wie mean here, and why not dass?

Here wie means how / in what way:

…erzählt, wie er … begonnen hat.
= “…tells how he started his career…”

If you used dass, the focus would change:

…erzählt, dass er … begonnen hat.
= “…tells that he started his career…”

So:

wie introduces the manner / the way in which something happened.
dass just states a fact.

Both are grammatically possible, but they don’t mean the same thing. The original sentence emphasizes the how, not just the bare fact.

Why is the verb order begonnen hat at the end of the clause?

The clause wie er vor einem Jahrzehnt seine Karriere in einer kleinen Firma begonnen hat is a subordinate clause (introduced by wie).

In German subordinate clauses with a compound verb (auxiliary + participle):

the past participle comes first,
the auxiliary comes last.

So:

… seine Karriere … begonnen hat (correct)
not … hat begonnen at that point in the sentence.

If there were only a simple verb in the present or simple past, it would just go at the end:

…, wie er seine Karriere beginnt.
…, wie er seine Karriere begann.

Why is erzählt in the present but hat begonnen in the past? Is that mixing tenses?

This is normal and correct in both German and English:

Mein Schwiegervater erzählt – he is currently telling the story (present).
… wie er … begonnen hat – he is telling about something that happened in the past (present perfect).

In English you’d do the same:

My father‑in‑law *is telling how he started his career…*

So there is no incorrect tense “mix” here; each clause uses the tense that fits its own time frame.

Why is it hat begonnen and not the simple past begann?

German has two main past tenses for completed actions:

Präteritum (simple past): begann
Perfekt (present perfect): hat begonnen

In spoken German, the Perfekt is usually preferred for most verbs:

Er hat seine Karriere begonnen. (sounds natural in conversation)

The Präteritum is more common:

in writing (especially narrative texts), or
with certain very common verbs (like war, hatte, ging, kam).

So hat begonnen is the typical choice in everyday speech. You could say wie er … seine Karriere … begann, especially in a written, narrative style, but it feels more literary or formal.

Why does beginnen take haben (hat begonnen) and not sein?

In the Perfekt, some verbs use sein, others haben:

sein is used mainly with:
- verbs of movement or change of state without a direct object
  - gehen → ist gegangen
  - sterben → ist gestorben
haben is used:
- with transitive verbs (verbs that take a direct object), and many others
  - lesen → hat gelesen
  - essen → hat gegessen

In your sentence:

er hat seine Karriere begonnen
beginnen here is transitive (it has a direct object: seine Karriere),
so the auxiliary is haben: hat begonnen, not ist begonnen.

Why is it vor einem Jahrzehnt and not vor ein Jahrzehnt? Which case is used?

The preposition vor in time expressions takes the dative case.

Jahrzehnt is neuter: das Jahrzehnt
Dative singular neuter: dem Jahrzehnt
With ein: einem Jahrzehnt

So:

vor einem Jahrzehnt = a decade ago
(vor
- dative)

If you wrote vor ein Jahrzehnt, that would be accusative and grammatically wrong in this context.

What’s the difference between vor einem Jahrzehnt and seit einem Jahrzehnt?

Both involve time, but they express different ideas:

vor einem Jahrzehnt = a decade ago
→ Refers to a single point in the past when something happened.
seit einem Jahrzehnt = for a decade / for ten years
→ Emphasizes duration up to now:
- Er arbeitet seit einem Jahrzehnt in dieser Firma.
  He has been working in this company for ten years (and still does).

In your sentence, the meaning is “He started his career a decade ago,” so vor is correct.

Could I say vor zehn Jahren instead of vor einem Jahrzehnt? Is there any difference?

Yes, you can say:

vor zehn Jahren = ten years ago
vor einem Jahrzehnt = a decade ago

They are almost equivalent in meaning. The difference is stylistic:

vor zehn Jahren is more everyday and common.
vor einem Jahrzehnt sounds a bit more formal or literary, or just slightly more “dramatic.”

Why is it in einer kleinen Firma and not in eine kleine Firma?

The preposition in can take either accusative or dative, depending on movement vs. location:

Accusative: movement into something
- Er geht in eine Firma. – He goes into a company (direction).
Dative: location in something
- Er arbeitet in einer Firma. – He works in a company (no movement).

In your sentence, in einer kleinen Firma describes where he began his career (location, not movement), so dative is used:

feminine noun Firma:
- nominative: die Firma
- dative: der Firma
- with eine: einer Firma
plus adjective: in einer kleinen Firma

Could I also say bei einer kleinen Firma instead of in einer kleinen Firma?

Yes, bei einer kleinen Firma is also possible, and very natural when talking about workplaces.

Subtle nuance:

bei einer Firma = with/for a company (as your employer)
in einer Firma = in a company (physically inside that organization, but also idiomatically “at a company”)

In many contexts about work, bei is slightly more typical:

Er hat seine Karriere bei einer kleinen Firma begonnen.

But in einer kleinen Firma is correct and commonly used as well.

Why is it seine Karriere and not sein Karriere?

Two things matter with possessive determiners:

Who owns the thing (person & gender of the possessor)
Gender, number, and case of the noun being possessed

Here:

Possessor: er (he) → base form sein-
Noun: Karriere (feminine, singular), and it’s the direct object (accusative).

For feminine singular in the accusative, the ending is -e:

seine Karriere

Compare:

sein Auto (neuter, accusative)
seinen Vater (masculine, accusative)
seine Karriere (feminine, accusative)

So sein Karriere would be incorrect; the correct form is seine Karriere.

Why is seine Karriere in the accusative case?

Karriere is the direct object of begonnen hat:

Wer? (who) hat begonnen? → er (subject, nominative)
Was? (what) hat er begonnen? → seine Karriere (direct object, accusative)

In German, direct objects normally take the accusative, so seine Karriere is in the accusative case.

Why is there a comma before wie?

In German, every finite subordinate clause (a clause with a conjugated verb) must be separated from the main clause by a comma.

Main clause: Mein Schwiegervater erzählt
Subordinate clause: wie er vor einem Jahrzehnt seine Karriere in einer kleinen Firma begonnen hat

Because wie introduces that subordinate clause, you must put a comma:

Mein Schwiegervater erzählt, wie er … begonnen hat.

Writing it without the comma would be incorrect in standard German spelling.