Die Firma ist reich.

In German, all nouns are capitalized, not just proper names.

So:

• die Firma = the company
• der Mann = the man
• das Haus = the house

This is one of the first big spelling differences English speakers notice.

Every German noun has a grammatical gender: masculine, feminine, or neuter.

Firma is a feminine noun, so its basic article is die:

• die Firma

This gender is grammatical, so it does not mean the company is literally female. It just affects articles, adjective endings, and pronouns later on.

Yes. Die can mean:

• the for a feminine singular noun
• the for all plural nouns in the nominative and accusative

In this sentence, it is feminine singular, because Firma is a singular feminine noun:

• die Firma

German main clauses normally follow the verb-second rule.

Here the sentence is:

• Die Firma = subject
• ist = verb
• reich = adjective/complement

So:

• Die Firma ist reich.

This is very similar to English The company is rich, except that German is stricter about the finite verb being in position 2 in main clauses.

Ist is the 3rd person singular form of the verb sein (to be).

Present tense of sein:

• ich bin = I am
• du bist = you are
• er/sie/es ist = he/she/it is
• wir sind = we are
• ihr seid = you are
• sie/Sie sind = they are / you are

Since die Firma is a singular noun, German uses ist.

Because reich is not being used before a noun here. It is being used after the verb ist as a predicate adjective.

In German:

• before a noun, adjectives usually take an ending
  
  • eine reiche Firma = a rich company
• after sein/werden/bleiben, adjectives usually do not take an ending
  
  • Die Firma ist reich. = The company is rich.

This is different from English only in spelling, since English also says the company is rich, not richly or riche.

It is an adjective.

After verbs like sein (to be), werden (to become), and bleiben (to remain), German often uses an adjective to describe the subject:

• Die Firma ist reich.
• Die Firma wird reich.
• Die Firma bleibt reich.

So reich describes die Firma.

No, not by itself.

If you use eine reiche, German expects a noun after it:

• Die Firma ist eine reiche Firma.

But that sounds repetitive and unnatural in most situations. The normal sentence is:

• Die Firma ist reich.

So when you simply want to describe the company, use the adjective after ist with no ending.

Usually, Firma means company or business.

Although English has the word firm, German learners should be careful: Firma is the normal everyday word for a company, especially in business contexts.

Examples:

• eine große Firma = a big company
• Ich arbeite bei einer Firma. = I work at a company.

Reich is pronounced approximately like rykh, with:

• ei sounding like English eye
• ch being the German ich/ach-type sound, depending on accent and speaker

A rough English approximation is rikeh without a strong final vowel, but that is not exact.

So:

• reich ≈ rykh

Also note that reich rhymes roughly with:

• gleich
• weich
• Teich

Yes, in many contexts it can.

But for most learners, company is the safest and most natural translation of Firma. English firm is possible, but it sounds a bit more formal or business-like depending on context.

So if you are learning basic vocabulary, think:

• die Firma = the company

Yes, but it changes the emphasis.

• Die Firma ist reich. = neutral statement
• Reich ist die Firma. = emphasizes reich, something like Rich is the company or The company is rich indeed

German allows this because the finite verb still stays in second position:

• Reich = position 1
• ist = position 2
• die Firma = later

This kind of word order is less neutral and more stylistic.

Because Firma is feminine, you would normally use sie:

• Die Firma ist reich. Sie ist sehr erfolgreich.
  = The company is rich. It is very successful.

This can feel strange to English speakers because English would usually use it, but German pronouns follow the noun’s grammatical gender:

• die Firma → sie

The plural of Firma is Firmen.

So:

• Die Firma ist reich. = The company is rich.
• Die Firmen sind reich. = The companies are rich.

Notice the changes:

• singular Firma → plural Firmen
• singular verb ist → plural verb sind
• die stays die in the nominative plural