Hij werd rijk met zijn eerste bedrijf.

Because werd is the past tense of worden, which means to become. So Hij werd rijk means He became rich, not He was rich.

• zijn = to be
• worden = to become

So:

• Hij was rijk = He was rich
• Hij werd rijk = He became rich

This is a very common pattern in Dutch: worden + adjective to express a change of state.

The basic form is worden.

Here are the most useful forms:

• infinitive: worden = to become
• present: ik word, hij wordt
• past singular: ik/hij werd
• past plural: wij/ze werden
• past participle: geworden

So werd is the singular simple past form.

Because rijk is being used as a predicate adjective, not directly before a noun.

Compare:

• een rijke man = a rich man
• Hij werd rijk = He became rich

In Hij werd rijk, rijk comes after a linking verb (werd) and describes the subject Hij, so it usually stays in its basic form, without -e.

Because eerste is an ordinal adjective placed before the noun bedrijf.

In Dutch, ordinal numbers used before nouns normally take -e:

• de eerste dag = the first day
• zijn eerste bedrijf = his first company/business

So the base idea is eerste = first, and before a noun it appears with that -e ending.

Because zijn is the normal Dutch possessive pronoun meaning his.

Dutch possessive pronouns do not change depending on the gender of the noun the way adjectives often do. So you simply get:

• zijn bedrijf = his company/business
• zijn auto = his car
• zijn eerste bedrijf = his first company/business

So zijn stays zijn.

Here bedrijf means company, business, or firm.

That makes zijn eerste bedrijf mean something like:

• his first company
• his first business
• the first business he started or owned

Dutch bedrijf is a common word for a commercial enterprise.

Here met means something like with, through, or by means of.

So rijk met zijn eerste bedrijf suggests that his first business was the means by which he became rich.

It does not necessarily mean he was physically together with the company; it expresses the instrument or source.

A natural English sense is:

• He became rich through his first business.

Sometimes yes, but the nuance is a little different.

• met zijn eerste bedrijf suggests the business was the means or vehicle
• door zijn eerste bedrijf can sound more like because of or as a result of that business

In this sentence, met is very natural because it fits the idea of becoming rich by means of that business activity.

This sentence has normal Dutch main-clause word order:

• Hij = subject
• werd = finite verb in second position
• rijk = complement
• met zijn eerste bedrijf = prepositional phrase

So:

Hij werd rijk met zijn eerste bedrijf.

Dutch main clauses usually put the finite verb in the second position. That is exactly what happens here.

Yes. Dutch often allows other elements to come first, as long as the finite verb still stays in second position.

For example:

• Met zijn eerste bedrijf werd hij rijk.

This is still correct. It puts more emphasis on met zijn eerste bedrijf.

Notice what happens:

• first comes Met zijn eerste bedrijf
• then the finite verb werd
• then the subject hij

That is standard Dutch inversion after a fronted element.

Because rijk is an adjective here, not a noun.

In Hij werd rijk, rijk describes Hij after the verb werd. Dutch does not use an article in that structure.

Compare:

• Hij werd rijk. = He became rich.
• Hij is een rijke man. = He is a rich man.

In the second sentence, rijke comes before the noun man, so the structure is different.

Yes, very common.

rijk worden is the normal everyday way to say to become rich.

Examples:

• Hij wil rijk worden. = He wants to become rich.
• Ze werd snel rijk. = She became rich quickly.
• Niemand wordt zomaar rijk. = Nobody just becomes rich.

So this sentence uses a very standard Dutch pattern.

rijk is pronounced roughly like the English word rake, but with a Dutch ij sound that is not exactly the same as English a.

A rough guide:

• r = a Dutch r, which varies by region
• ij = similar to the vowel in some pronunciations of English time or say, but not identical
• k = clear k

For an English speaker, a rough approximation is rike, but the real Dutch vowel is worth listening to from native audio.

A rough pronunciation is buh-DRAYF or buh-DRIFE, but neither is perfect.

A few important points:

• stress is on the second syllable: be-DRIJF
• ij is the same vowel as in rijk
• the final f is clearly pronounced

So the stress pattern matters a lot: not BE-drijf, but be-DRIJF.

Bedrijf is a het word:

• het bedrijf = the company/business

That matters in some situations, for example with articles and adjectives:

• het eerste bedrijf = the first company

But in zijn eerste bedrijf, the possessive zijn replaces the article, so you do not see het in the sentence itself.

It is in the simple past.

The past meaning comes from werd, the past tense of worden.

So the sentence presents the event as something completed in the past:

• Hij wordt rijk = He is becoming rich / He becomes rich
• Hij werd rijk = He became rich

This is the normal past-tense way to describe how someone became rich.