Der Hund frisst Brot.

Because Hund is a masculine noun in German. Its dictionary form is der Hund.

In this sentence, der Hund is the subject, so it is in the nominative case. For a masculine noun in the nominative singular, the definite article is der.

So:

• der Hund = the dog

This is about grammatical gender, not necessarily biological sex.

Not always. In German, grammatical gender and real-life sex are not the same thing.

• der Hund is the normal dictionary word for dog
• it can refer to a dog in general
• if you specifically mean a female dog, German often uses die Hündin

So in many contexts, der Hund can simply mean the dog, without emphasizing that it is male.

Because fressen is the infinitive form, meaning to eat.

In the sentence, the verb has to be conjugated to match the subject der Hund = he/it. In the present tense, fressen changes like this:

• ich fresse
• du frisst
• er/sie/es frisst
• wir fressen
• ihr fresst
• sie/Sie fressen

So with der Hund, you use:

• Der Hund frisst. = The dog eats.

Notice that this verb is a little irregular because the stem vowel changes from e to i in du and er/sie/es forms.

Both relate to eating, but they are used differently.

• essen / isst is the normal verb for people
• fressen / frisst is usually used for animals

So:

• Der Mann isst Brot. = The man eats bread.
• Der Hund frisst Brot. = The dog eats bread.

If you use fressen for a person, it can sound rude or insulting, as if the person is eating like an animal.

German often leaves out the article with food or other uncountable/general substances when the meaning is simply some bread or bread in general.

So:

• Der Hund frisst Brot. = The dog eats bread.

This sounds natural.

You could also say:

• Der Hund frisst das Brot. = The dog is eating the bread.
• Der Hund frisst ein Brot. = The dog is eating a loaf/bread item
  This is less likely in many contexts unless you really mean one whole bread item.

So the version without an article is perfectly normal.

Brot is in the accusative case because it is the direct object of the verb frisst.

The dog is doing the action, and the bread is receiving the action:

• Der Hund = subject
• frisst = verb
• Brot = direct object

A useful thing to know is that Brot is a neuter noun: das Brot.

For neuter nouns, the definite article is the same in nominative and accusative:

• nominative: das Brot
• accusative: das Brot

In your sentence, there is no article, so you just see Brot.

Yes. In a normal German main clause, the conjugated verb usually goes in second position.

So in:

• Der Hund frisst Brot.

the order is:

1. Der Hund
2. frisst
3. Brot

This is the standard pattern: subject + verb + object.

German can move things around for emphasis, but the finite verb still usually stays in second position in a statement.

For example:

• Brot frisst der Hund.

This is grammatical, but it sounds marked or emphatic, like It’s bread that the dog eats.

For a yes/no question in German, the conjugated verb usually comes first:

• Frisst der Hund Brot? = Is the dog eating bread? / Does the dog eat bread?

So the statement:

• Der Hund frisst Brot.

becomes the question:

• Frisst der Hund Brot?

Because all nouns are capitalized in German.

So:

• Hund is a noun
• Brot is a noun

That is why they begin with capital letters, even in the middle of a sentence.

This is one of the most noticeable differences from English.

Yes. frisst is present tense.

So Der Hund frisst Brot. can mean:

• The dog eats bread.
• The dog is eating bread.

German simple present often covers both the English simple present and present progressive, depending on context.

A simple English-style approximation is:

• dair hoont frisst broht

A few notes:

• der has an r that is usually softer than in many English accents
• Hund has a short u, not the English sound in fun
• frisst has a short i, like in sit
• Brot has a long o sound

If you want to sound more natural, listening to native audio is especially helpful for r and the vowels.

You might hear that sometimes, and native speakers would understand it, but the more typical and idiomatic choice for an animal is:

• Der Hund frisst Brot.

So for a learner, it is best to remember:

• people: essen
• animals: fressen

That will usually give you the most natural German.