Frisches Brot hält nicht lange.

Because Brot is a neuter noun (das Brot), and the adjective frisch has to take an ending.

Here there is no article before the noun, so the adjective has to show the grammatical information by itself. In the nominative singular neuter, that ending is -es:

• frisches Brot = fresh bread

This is called adjective inflection.

German often leaves out the article when speaking generally about something.

So Frisches Brot hält nicht lange means something like:

• Fresh bread doesn’t keep long
• Fresh bread doesn’t last long

It is a general statement about fresh bread in general, not about one specific loaf.

If you were talking about a specific bread, you might say:

• Das frische Brot hält nicht lange.
  = The fresh bread doesn’t last long.

Because all nouns are capitalized in German.

So:

• Brot = noun → capitalized
• frisches = adjective → not capitalized
• hält = verb → not capitalized
• lange = adverb → not capitalized

This is one of the most noticeable spelling rules in German.

Because the subject is Brot, which is third person singular: it.

The verb is halten, and in the present tense its er/sie/es form is:

• ich halte
• du hältst
• er/sie/es hält
• wir halten
• ihr haltet
• sie/Sie halten

Since Brot = es (it), the correct form is hält.

Halten is a strong verb that changes its stem vowel in the present tense for du and er/sie/es:

• halten
• du hältst
• er/sie/es hält

This kind of vowel change is something you just have to learn with certain verbs. It is similar to English irregular patterns like sing / sings or go / goes, except in German the stem itself changes.

Not in this sentence.

Although halten often means to hold, it has several meanings. Here hält nicht lange means:

• doesn’t last long
• doesn’t keep long

So in this context, it is about how long fresh bread stays good.

This is a very common thing in German: one verb can have several related meanings depending on context.

Here lange means for a long time or long in the sense of duration.

So:

• nicht lange = not long
• hält nicht lange = doesn’t last long

In this sentence, lange is functioning as an adverb, not an adjective.

Compare:

• ein langes Brot = a long loaf/bread → adjective describing shape/length
• Das Brot hält lange. = The bread lasts a long time. → adverb describing duration

Because nicht usually goes before the part of the sentence it is negating.

Here it is negating lange:

• hält nicht lange = does not last long

So the idea is not that the bread doesn’t exist or isn’t held; the idea is specifically that its duration is not long.

This placement is very natural in German.

The sentence follows the normal German main-clause pattern:

• Subject: Frisches Brot
• Verb: hält
• Other information: nicht lange

So it is basically:

• Frisches Brot | hält | nicht lange.

This is a standard verb-second sentence in German. Since the subject comes first, the finite verb comes second.

Yes, you could, but it means something slightly different.

• Frisches Brot hält nicht lange.
  = Fresh bread doesn’t keep / doesn’t last long.

• Frisches Brot bleibt nicht lange frisch.
  = Fresh bread doesn’t stay fresh for long.

The second version is more explicit about freshness, while the original is a more natural, compact way to express the general idea.

A simple pronunciation guide is:

FRIH-shess broht helt nikht LANG-uh

A few helpful points:

• Frisches: the sch sounds like English sh
• Brot: long o sound
• hält: the ä sounds somewhat like the vowel in care for many learners, though not exactly
• nicht: the ch is the soft German sound, not a hard k
• lange: two syllables, LANG-uh

If you want to sound natural, the stress is usually strongest on Brot and lange.