Learn Hardcore German: Mein Freund hat einen starken Akzent, aber ein Muttersprachler findet seine Sätze trotzdem gut verständlich. - My friend has a strong accent, but a native speaker still finds his sentences easy to understand.

You could also say Mein Freund spricht mit starkem Akzent (“My friend speaks with a strong accent”), but haben + Akzent is the most straightforward equivalent to English “to have an accent.”

Why is it einen starken Akzent and not ein starker Akzent?

This is about case and adjective endings.

Case:
The verb haben takes a direct object in the accusative case.
- Masculine singular:
  - Nominative: ein starker Akzent (as subject)
  - Accusative: einen starken Akzent (as object)
Here, Akzent is the direct object of hat, so it must be accusative:
→ einen instead of ein.
Adjective ending:
With a masculine accusative noun and an indefinite article (ein), the adjective takes -en:
- einen starken Akzent

So the full form einen starken Akzent is exactly what you expect:
masculine + accusative + indefinite article + adjective → einen starken Akzent.

What’s the difference between Akzent and Dialekt?

Roughly:

Akzent = accent: how you pronounce, especially foreign or regional pronunciation when speaking a language that is not your native one.
- Er spricht Deutsch mit starkem französischem Akzent.
Dialekt = dialect: a regional variety of the language with its own vocabulary, grammar, and pronunciation.
- Sie spricht schwäbischen Dialekt.

In your sentence, Akzent is correct because the focus is on pronunciation and understandability, not on speaking a distinct regional variety with different words and grammar.

What does Muttersprachler mean, and is it masculine or feminine?

Muttersprachler means “native speaker (of a language)”.

Grammatically:

der Muttersprachler – masculine (singular)
die Muttersprachlerin – feminine (singular)
die Muttersprachler – plural (for groups of mixed or unspecified gender)
die Muttersprachlerinnen – plural (for specifically female native speakers)

In the sentence aber ein Muttersprachler findet …, ein Muttersprachler is masculine singular and can mean “a native speaker” in a general, generic way (not talking about a particular known person).

Why is it ein Muttersprachler (singular) and not Muttersprachler in the plural, if we mean “native speakers” in general?

German, like English, often uses a singular noun with an indefinite article to talk about people in general:

Ein Lehrer muss geduldig sein. – A teacher has to be patient. (teachers in general)
Ein Arzt studiert viele Jahre. – A doctor studies for many years. (doctors in general)

Similarly:

Ein Muttersprachler findet seine Sätze trotzdem gut verständlich.
= “A native speaker would still find his sentences easy to understand.”
→ This describes what any typical native speaker would experience.

You could also say:

Muttersprachler finden seine Sätze trotzdem gut verständlich. – “Native speakers find his sentences easy to understand.”

Both are correct; the singular with ein simply presents a kind of “typical representative” of the group.

What does trotzdem mean here, and where can it go in the sentence?

trotzdem means roughly “nevertheless / still / in spite of that.”

Functionally, it’s a sentence adverb (often called a “conjunctional adverb”), and it usually appears in the “V2 slot” region, with the finite verb as the second element in the clause.

In your sentence:

… aber ein Muttersprachler findet seine Sätze trotzdem gut verständlich.

Here trotzdem is inside the middle field, after the subject ein Muttersprachler and verb findet. That’s very natural.

Other common placements:

… aber trotzdem findet ein Muttersprachler seine Sätze gut verständlich.
… aber ein Muttersprachler findet sie trotzdem gut verständlich.

All three are acceptable, but:

putting trotzdem right after aber (aber trotzdem …) makes the contrast especially clear;
putting trotzdem right before the part it modifies (here, gut verständlich) is also common.

One placement that would be wrong is:

✗ … aber ein Muttersprachler trotzdem findet seine Sätze gut verständlich.
(The verb findet must stay in second position in its clause.)

Why does the sentence use both aber and trotzdem? Aren’t they both like “but”?

They have related but different roles:

aber = “but / however” – a coordinating conjunction linking two clauses (like English but).
trotzdem = “nevertheless / still / in spite of that” – an adverb that comments on the whole second clause.

In your sentence:

Mein Freund hat einen starken Akzent – fact A.
aber … – introduces a contrast.
… ein Muttersprachler findet seine Sätze trotzdem gut verständlich. – fact B, despite fact A.

So the structure is:

aber → “but” (connects the two statements)
trotzdem → “nevertheless / still” (adds the idea: in spite of his strong accent)

You can grammatically drop trotzdem:

… aber ein Muttersprachler findet seine Sätze gut verständlich.

This is still correct, but less explicit about the “in spite of” nuance.
Or you could drop aber and start a new sentence:

Mein Freund hat einen starken Akzent. Trotzdem findet ein Muttersprachler seine Sätze gut verständlich.

Both elements together just make the contrast very clear and natural-sounding.

Who does seine in seine Sätze refer to, and how do I know when to use sein vs. ihr?

In this sentence, seine refers back to Mein Freund.

Mein Freund is masculine → use sein- for possession:
- sein Akzent – his accent
- seine Sätze – his sentences (plural)

General rule:

Use sein- for masculine or neuter owners:
- der Mann → sein Auto (the man → his car)
- das Kind → sein Buch (the child → its/his/her book, depending on context)
Use ihr- for feminine or plural owners:
- die Frau → ihr Auto (the woman → her car)
- die Kinder → ihr Spielzeug (the children → their toy(s))

In seine Sätze, the form seine is:

base sein- (because of Freund, masculine), plus
-e ending for plural accusative (Sätze).

So: seine Sätze = sentences that belong to him (the friend).

What exactly does gut verständlich mean here, and how is it built grammatically?

gut verständlich means roughly “easy to understand / quite comprehensible.”

Grammatically:

verständlich is an adjective = “understandable / comprehensible.”
gut is an adverb modifying that adjective = “well, easily, clearly.”

In the sentence … findet seine Sätze trotzdem gut verständlich:

findet … verständlich works like English “finds … understandable.”
gut intensifies it → “finds his sentences very / easily understandable.”

Because verständlich is used as a predicate adjective (after the verb finden), it does not take an ending here:

Die Sätze sind verständlich. – The sentences are understandable.
Ich finde die Sätze verständlich. – I find the sentences understandable.

So you get gut verständlich, without extra endings.

Why does the sentence say findet seine Sätze gut verständlich instead of simply versteht seine Sätze gut?

Both are possible, but they say slightly different things:

ein Muttersprachler versteht seine Sätze gut
= “a native speaker understands his sentences well”
→ Focus on the actual act of understanding.
ein Muttersprachler findet seine Sätze gut verständlich
= “a native speaker finds his sentences easy to understand”
→ Focus on the quality of the sentences: they are easy to understand in general.

Using finden + Adjektiv is a common way in German to express a subjective evaluation:

Ich finde den Film langweilig. – I find the film boring.
Sie findet das Buch interessant. – She finds the book interesting.

So here findet … gut verständlich evaluates his sentences as (very) comprehensible, which matches the idea of “despite his strong accent, they’re still easy to follow.”