Learn Hardcore German: Jedes Mal freue ich mich, wenn der Hund im Garten spielt. - Every time I am happy when the dog plays in the garden.

Because Jedes Mal is put first for emphasis, the verb freue has to come next, and the subject ich moves after the verb. This inversion (verb before subject) is completely normal in German whenever you start a main clause with something other than the subject.

If you started with the subject instead, you’d say:

Ich freue mich jedes Mal, wenn der Hund im Garten spielt.

The meaning is the same; the difference is just emphasis and style.

Why do we need mich in freue ich mich? Can we just say Ich freue?

No, you cannot say Ich freue by itself. Sich freuen is a reflexive verb in German; it normally requires a reflexive pronoun.

Infinitive: sich freuen (to be glad / to be pleased)
1st person singular: ich freue mich
2nd person singular: du freust dich
3rd person singular: er/sie/es freut sich

So in this sentence, freue … mich belongs together:
Jedes Mal freue ich mich, … = “Every time, I am happy / I’m glad when …”

Without mich, the verb form would be incomplete or sound wrong to a native speaker.

Why is there a comma before wenn, and why does spielt go at the end of that clause?

In German, wenn introduces a subordinate clause (a Nebensatz). Subordinate clauses are separated from the main clause by a comma, and the finite verb goes to the end of that subordinate clause.

Main clause:

Jedes Mal freue ich mich, …
– finite verb freue in 2nd position.

Subordinate clause:

… wenn der Hund im Garten spielt.
– subordinator wenn first, finite verb spielt at the end.

So the structure is:

[Main clause], [wenn + subject + other stuff + verb at the end].

This verb-final order is a key feature of German subordinate clauses.

What is the difference between wenn, als, and wann in this kind of sentence?

In time-related sentences:

wenn = “whenever / when(ever)” in the sense of things that can happen repeatedly or in general:
- Ich freue mich, wenn der Hund im Garten spielt.
  “I’m happy whenever the dog plays in the garden.”
als = “when” for single events in the past:
- Ich habe mich gefreut, als der Hund im Garten gespielt hat.
  “I was happy when the dog played in the garden (that one time in the past).”
wann usually means “when?” as a question word, or in indirect questions:
- Wann spielt der Hund im Garten? – “When does the dog play in the garden?”
- Ich weiß nicht, wann der Hund im Garten spielt. – “I don’t know when the dog plays in the garden.”

In your sentence, because it describes something that happens every time, wenn is the correct choice.

Why is it der Hund and not den Hund or dem Hund?

Der Hund is in the nominative case, because it is the subject of the subordinate clause.

der Hund (nominative) – subject: the dog (who is playing)
den Hund (accusative) – direct object: the dog (who is being seen, fed, etc.)
dem Hund (dative) – indirect object: to/for the dog

In … wenn der Hund im Garten spielt, the dog is doing the action of playing, so you must use the nominative der Hund.

What exactly is going on with im Garten? Why not in dem Garten, and why this case?

Im is a contraction of in dem:

in (preposition) + dem (dative article for masculine/neuter singular)
→ im

Garten is masculine (der Garten). With the preposition in, German uses:

dative for location (“where?”)
accusative for direction (“where to?”)

Here, the dog is located in the garden, not moving into it. So you need dative:

wo? (where?) → im Garten = in dem Garten (dative)

If you wanted to say “into the garden,” you’d use accusative:

in den Garten (movement to a place)

What gender and case does Garten have here, and how can I see it?

The base noun is der Garten (masculine).

In the phrase im Garten:

Garten is masculine singular.
The article dem (dative masculine singular) is hidden inside im (in dem → im).
Because of the preposition in
- “where?” (location), the case is dative.

So:
Garten = masculine noun, dative singular in this context.

Could I also say Ich freue mich jedes Mal, wenn der Hund im Garten spielt? Is there any difference?

Yes, that sentence is perfectly correct:

Ich freue mich jedes Mal, wenn der Hund im Garten spielt.

The difference is mainly word order and emphasis:

Jedes Mal freue ich mich, …
– Emphasis a bit more on “every time.”
Ich freue mich jedes Mal, …
– More neutral; focus slightly more on “I’m happy.”

Both are natural and mean the same thing in most contexts.

Could I drop jedes Mal and just say Immer freue ich mich, wenn der Hund im Garten spielt?

Yes, that is also grammatical and natural:

Immer freue ich mich, wenn der Hund im Garten spielt.
Or more neutrally: Ich freue mich immer, wenn der Hund im Garten spielt.

Immer = “always”; jedes Mal = “every time.”
In many contexts, they overlap in meaning, but:

jedes Mal highlights each individual occasion.
immer emphasizes a continuous or very regular pattern.

In everyday speech, both would be understood similarly here.

Why is Mal in Jedes Mal capitalized? I’ve also seen mal in lowercase.

German distinguishes between:

Mal (capital M) as a noun meaning “time / occasion”:
- jedes Mal – “every time”
- ein Mal – “one time” (often written einmal)
mal (lowercase) as a little particle used in speech to soften commands or statements:
- Komm mal her! – “Come here (a sec)!”
- Sag mal, … – “Tell me, … / Say, …”

In Jedes Mal freue ich mich …, Mal is a noun (“every time”), so it’s capitalized.

Why is it spielt and not a form like “is playing” in German?

German doesn’t have a separate continuous tense like English (“is playing,” “was playing”). The simple present often covers both:

Der Hund spielt im Garten.
→ “The dog plays in the garden” / “The dog is playing in the garden.”

So in wenn der Hund im Garten spielt, the simple present spielt is used, and you can translate it naturally as “when the dog plays / when the dog is playing.”

Can I change the clause order: Wenn der Hund im Garten spielt, freue ich mich jedes Mal?

Yes, that is completely correct:

Wenn der Hund im Garten spielt, freue ich mich jedes Mal.

Here’s what changes:

The sentence starts with the wenn-clause (subordinate clause).
After the comma, the main clause starts, and again the finite verb freue must be in second position:
- freue (verb)
- ich (subject)
- mich jedes Mal (rest)

Word order options (all correct, with slight differences in rhythm/emphasis):

Jedes Mal freue ich mich, wenn der Hund im Garten spielt.
Ich freue mich jedes Mal, wenn der Hund im Garten spielt.
Wenn der Hund im Garten spielt, freue ich mich jedes Mal.

All three are natural German.