Learn Hardcore German: Ich kaufe Futter für den Hund.

Der Hund is the nominative form (used for the subject of the sentence).
In this sentence, Hund is not the subject. The subject is Ich (I).

Ich = subject (nominative)
Futter = direct object (what is being bought)
den Hund = part of the prepositional phrase für den Hund (for the dog)

The preposition für always takes the accusative case.
For masculine nouns like Hund, the accusative form of der is den:

Nominative: der Hund (the dog – as subject)
Accusative: den Hund (the dog – as object)

So für den Hund is required by the grammar of für.

Why does für use the accusative case?

Some German prepositions are fixed to a particular case; you simply have to learn them with that case.

Für is always followed by the accusative:

für den Hund
für die Katze
für das Kind
für die Kinder

It never uses dative or genitive. So whenever you see für, expect the noun after it to be in accusative form.

Why is it kaufe and not kaufen or kauft?

Kaufen is the infinitive (the dictionary form: to buy).

The verb has to agree with the subject Ich (I).
Present tense conjugation of kaufen:

ich kaufe – I buy / am buying
du kaufst – you buy (singular, informal)
er/sie/es kauft – he/she/it buys
wir kaufen – we buy
ihr kauft – you buy (plural, informal)
sie/Sie kaufen – they / you (formal) buy

Because the subject is Ich, the correct form is kaufe.

Could I also say Ich kaufe für den Hund Futter? Is that wrong?

That word order is grammatically correct:

Ich kaufe Futter für den Hund.
Ich kaufe für den Hund Futter.

Both are possible.

The first version (Ich kaufe Futter für den Hund) is more neutral and very common.
The second version (Ich kaufe für den Hund Futter) puts a bit more emphasis on für den Hund, as if you’re focusing on for whom you’re buying the food.

In everyday speech, the original sentence is slightly more natural, but both are fine.

Why is it Futter and not Essen for “food”?

German makes a distinction that English usually does not:

Futter = food for animals (pet food, animal feed)
Essen = food for humans, or the act of eating

So:

Ich kaufe Futter für den Hund. = I’m buying food for the dog. (dog food)
Ich kaufe Essen für meine Familie. = I’m buying food for my family.

If you said Essen für den Hund, people would understand, but it would sound odd, like you are treating the dog very much like a human at the level of wording.

What are the genders of Futter and Hund, and what are their articles?

Hund is masculine:
- Singular: der Hund (nominative)
- Accusative: den Hund
- Plural: die Hunde
Futter is neuter:
- Singular (and usually mass/uncountable): das Futter
- It’s typically used without a plural; you normally don’t say multiple “Futter” in everyday German.

In this sentence, Futter has no article because it’s used like a mass noun, similar to English I’m buying food (not a food). If you want to specify, you can say das Futter, Hundefutter (dog food), etc.

Could I say Ich kaufe dem Hund Futter instead of für den Hund? What’s the difference?

Yes, Ich kaufe dem Hund Futter is also correct, but the meaning is a little different in nuance.

Ich kaufe Futter für den Hund.
Focus: the purpose of the food – it is for the dog.
Ich kaufe dem Hund Futter.
Focus: you are doing something for the dog’s benefit, like “I’m buying the dog some food.”
Grammatically: dem Hund is dative (indirect object), like “to/for the dog”.

Both are natural. Für den Hund directly states who the food is for. Dem Hund Futter kaufen feels a bit more like doing the dog a favor or providing for it.

If the dog is female, do I still say den Hund?

Grammatically, Hund is masculine, so the forms stay masculine:

der Hund (subject)
den Hund (after für, accusative)

Even if the actual dog is female, many people still say der Hund / den Hund.

If you want to emphasize that the dog is female, you can use Hündin (bitch, female dog):

Nominative: die Hündin
Accusative: die Hündin

Then the sentence would be:

Ich kaufe Futter für die Hündin.

But in everyday language, people often just use Hund for dogs of any sex.

Can I drop Ich, like in Spanish or Italian, and just say Kaufe Futter für den Hund?

Normally, no. In German, you almost always include the personal pronoun:

Ich kaufe Futter für den Hund. ✅

Dropping Ich:

Kaufe Futter für den Hund. ❌ (sounds like an incomplete sentence)

The only time you might omit Ich is in very informal notes, headlines, or commands aren’t formed this way either (they use the imperative). For a normal sentence, keep Ich.

How would I say “I’m going to buy food for the dog” (future meaning)? Do I need a future tense?

German often uses the present tense for future meaning, just like in English I’m buying food tomorrow:

Ich kaufe morgen Futter für den Hund. = I’m going to buy food for the dog tomorrow.

If you want to use an explicit future tense, you can:

Ich werde Futter für den Hund kaufen. = I will buy / I am going to buy food for the dog.

Both are correct. In daily speech, the present tense + time expression (like morgen, später) is more common.

How do I pronounce Ich, kaufe, Futter, für, and Hund?

Very roughly, in English-friendly terms:

Ich:
- ch is a soft sound, like blowing air through a narrow opening, similar to the h in huge, but farther back in the mouth. Not like English k or ch in church.
kaufe:
- kau- = like cow
- final -e is a short, unstressed sound (like the a in sofa): KOW-fuh.
Futter:
- u = like oo in book, not like oo in food.
- Double t just means a short, crisp t.
- Stress on the first syllable: FUT-ter.
für:
- ü has no direct English equivalent; shape your lips like oo in food, but say ee inside → a front rounded vowel.
- Very roughly like fyur, but with that special ü sound.
Hund:
- u again like oo in book.
- Final d in normal speech can sound almost like a soft t.
- So more like Hoont (but with a shorter vowel).