Sediul social apare în registrul comerțului.

It is a legal/business term. It usually means a company’s registered office or official registered address, not just any office where people work.

A few useful nuances:

• sediu can mean headquarters, seat, or premises depending on context.
• social here does not mean social in the everyday English sense of friendly/socializing. In legal Romanian, it means something like corporate or company-related.

So sediul social is a fixed expression in company law.

Because -ul is the Romanian definite article attached to the end of the noun.

• sediu = a registered office / an office / a headquarters
• sediul = the registered office / the office / the headquarters

Romanian usually puts the at the end of the noun instead of using a separate word like English does.

Sediu is actually a neuter noun.

Romanian neuter nouns behave:

• like masculine in the singular
• like feminine in the plural

So in the singular, a neuter noun often looks masculine:

• un sediu
• sediul

That is why sediul may look masculine even though sediu is classified as neuter.

Because in Romanian, adjectives often come after the noun.

So:

• sediul social = literally the office registered/corporate
• natural English translation: the registered office

Also, the definite article is attached to the noun, not repeated on the adjective:

• sediul social not
• sediul socialul

The adjective social agrees with the noun, but in this form its ending does not visibly change.

Apare is the 3rd person singular present tense of the verb a apărea.

So it means:

• appears
• shows up
• in official/legal language, often is listed or is shown

In this sentence, it can sound more formal than everyday appears. In context, it often suggests that the registered office is recorded in or shown in the register.

În means in or inside.

Here it introduces the place where something appears or is recorded:

• în registrul comerțului = in the trade register / in the commercial register

Romanian commonly uses în for information that appears in:

• a register
• a document
• a database
• a list

For the same reason as sediul: it is definite.

• registru = a register
• registrul = the register

So registrul comerțului literally means the register of trade/commerce.

Comerțului is the genitive singular definite form of comerț.

Here it means:

• of trade
• of commerce

So:

• registrul comerțului = literally the register of commerce/trade

The ending -ului is very common for masculine and neuter nouns in the singular genitive/dative when they are definite.

Compare:

• comerț = trade, commerce
• comerțului = of the trade / of commerce

In natural English, we usually do not translate it word-for-word; we say the Trade Register or the Commercial Registry.

Yes. It is a standard legal/business phrase in Romanian.

Very often, when referring to the official institution, you will see it written as:

• Registrul Comerțului

with capital letters.

So:

• lowercase: can be more generic or stylistic
• capitals: often the official name of the institution

Yes, but the original order is the most neutral one.

Neutral order:

• Sediul social apare în registrul comerțului.

Possible alternative for emphasis:

• În registrul comerțului apare sediul social.

That version puts more focus on where it appears. Romanian word order is more flexible than English, but the original sentence is the most straightforward and standard.

Not necessarily. In administrative or legal language, a apărea often means that information is shown, recorded, or listed somewhere.

So in this sentence, the meaning is not usually that something suddenly “appears” in a dramatic sense. It is more like:

• it is present in the record
• it is entered in the register
• it is listed there

The main special letters here are:

• ă in apare’s infinitive a apărea
  This is like the a in English about.

• î in în
  This sound does not exist exactly in English. It is a central vowel, pronounced with the tongue high and centered.

• ț in comerțului
  This is ts, like the end of cats.

A rough pronunciation guide for some words:

• sediul ≈ SEH-dee-ool
• apare ≈ a-PA-re
• în ≈ a short central vowel, no exact English match
• comerțului ≈ ko-MERT-su-lui

These are only approximations, but they help an English speaker get close.