Die Jahresgebühr ist niedrig.

Because Gebühr is a feminine noun in German, so it takes the feminine definite article die in the nominative singular.

• die Gebühr = the fee
• die Jahresgebühr = the annual fee

The word Jahresgebühr keeps the gender of its main noun, which is Gebühr.

German very often combines nouns into a single compound noun.

Here:

• Jahr = year
• Gebühr = fee

Together, they form Jahresgebühr = annual fee or literally year’s fee.

The -s- in the middle is a common linking element in German compounds. It does not always have a separate meaning; it just helps connect the parts smoothly.

The -es comes from Jahr and acts as a linking form in the compound.

So:

• Jahr
• Jahres-
• Jahresgebühr

This is very common in German compound nouns:

• Jahresende = end of the year
• Jahresbericht = annual report
• Jahresgebühr = annual fee

You do not need to translate the -es separately every time. It is just part of how the compound is formed.

In a normal German statement, the conjugated verb usually comes in the second position. This is one of the most important word-order rules in German.

Here:

• Die Jahresgebühr = subject
• ist = verb
• niedrig = adjective/predicate

So the structure is:

Subject + verb + complement

That is why you get Die Jahresgebühr ist niedrig.

Because niedrig comes after ist and is being used as a predicate adjective. Predicate adjectives in German do not take adjective endings.

Compare:

• Die Jahresgebühr ist niedrig.
  Here niedrig is after the verb ist, so it stays in its basic form.

• die niedrige Jahresgebühr
  Here niedrige comes before the noun, so it needs an adjective ending.

This is a very important difference in German.

Yes, you could sometimes use other words, but they are not always exactly the same.

• niedrig = low
  Often used for prices, levels, rates, fees, numbers
• gering = small, low, slight
  A bit more formal; often about amount or degree
• günstig = favorable, inexpensive, good value
  Often sounds more positive from the buyer’s point of view

So:

• Die Jahresgebühr ist niedrig. = The annual fee is low.
• Die Jahresgebühr ist gering. = The annual fee is small/low. Slightly more formal.
• Die Jahresgebühr ist günstig. = The annual fee is inexpensive/good value.

All can work depending on context, but niedrig is very straightforward here.

Because all nouns in German are capitalized.

In this sentence:

• Jahresgebühr is a noun, so it begins with a capital letter.
• niedrig is an adjective, so it is not capitalized.

This is a basic German spelling rule:

• nouns = capitalized
• adjectives, verbs, etc. = usually lowercase

It is in the nominative case, because it is the subject of the sentence.

You can ask:

• Was ist niedrig? = What is low?

Answer:

• Die Jahresgebühr.

Since it is the subject, nominative is used:

• die Jahresgebühr

In most normal sentences, no. You usually need an article or some other determiner before a singular countable noun in German, just as in English you usually need the or an.

So the standard sentence is:

• Die Jahresgebühr ist niedrig.

Without die, it sounds incomplete in ordinary usage.

A rough guide is:

YAH-res-guh-BYOOR

A bit more carefully:

• Jahres sounds roughly like YAH-res
• Gebühr has a long ü sound, which does not exist exactly in English

For ü, try saying ee while rounding your lips as if saying oo.

Also:

• the stress is mainly on -bühr in Gebühr
• the J in German is pronounced like English y

Yes. A literal translation like The yearly fee is low is possible and understandable.

But in natural English, annual fee is usually the most idiomatic equivalent of Jahresgebühr.

So:

• Die Jahresgebühr ist niedrig.
• most natural English: The annual fee is low.

No, that changes the meaning and sounds unnatural.

• Jahresgebühr is a noun meaning annual fee
• jährlich is an adverb or adjective meaning yearly/annually

So:

• Die Jahresgebühr ist niedrig. = The annual fee is low.
• Die Gebühr ist jährlich niedrig. would suggest something like The fee is low on a yearly basis, which is not the normal way to express this idea.

If you want to describe the kind of fee, the compound noun Jahresgebühr is the natural choice.

It is neutral and works in both formal and informal contexts.

It would fit well in:

• advertisements
• product descriptions
• website information
• everyday conversation

There is nothing especially formal or casual about the grammar. It is a simple, standard German sentence.