Tiu regulo ne estas universala.

Tiu means that.

So Tiu regulo = that rule.

The difference is:

• tiu = that
• ĉi tiu = this

Examples:

• Tiu libro estas interesa. = That book is interesting.
• Ĉi tiu libro estas interesa. = This book is interesting.

In your sentence, tiu points to a specific rule that is not close to the speaker in the way this would be.

Because regulo is the subject of the sentence, not the direct object.

Esperanto uses -n mainly for:

• the direct object
• sometimes for direction

Here, Tiu regulo is the thing being described:

• Tiu regulo = the subject
• ne estas universala = is not universal

So no -n is needed.

Compare:

• Tiu regulo estas simpla. = That rule is simple.
• Mi lernas tiun regulon. = I am learning that rule.

In the second sentence, regulon has -n because it is the object of lernas.

In Esperanto, ne usually goes directly before the word or idea it negates.

Here it negates the verb phrase:

• ne estas = is not

So:

• Tiu regulo ne estas universala. = That rule is not universal.

This is the normal way to make a sentence negative in Esperanto.

Compare:

• Li ne venas. = He is not coming.
• Ŝi ne komprenas. = She does not understand.

Because universala is an adjective, meaning universal.

In this sentence, Esperanto is saying:

• The rule is universal or
• The rule is not universal

So universala describes regulo.

Structure:

• regulo = noun
• universala = adjective describing that noun

This is similar to English:

• The rule is universal.

If you wanted to say something like a universal rule, Esperanto would also use the adjective:

• universala regulo = a universal rule

Because -a is the normal ending for adjectives in Esperanto.

Basic endings:

• -o = noun
• -a = adjective
• -e = adverb
• -i = infinitive verb

So:

• regulo = rule
• universala = universal

The adjective must have the adjective ending -a.

Yes. In Esperanto, adjectives agree with the nouns they describe in number and case.

Here:

• regulo is singular
• it is not accusative
• so the adjective is simply universala

If the noun changed, the adjective would change too:

• Tiu regulo estas universala. = singular
• Tiuj reguloj estas universalaj. = plural
• Mi lernas tiun regulon universalan. = singular accusative
• Mi lernas tiujn regulojn universalajn. = plural accusative

So in your sentence, universala matches regulo.

Esperanto does not have an indefinite article like English a/an.

So:

• regulo can mean a rule or just rule, depending on context.

Esperanto does have a definite article:

• la = the

But in this sentence, tiu already makes the noun definite and specific:

• tiu regulo = that rule

Because of that, you do not use la here.

Not:

• la tiu regulo

Just:

• tiu regulo

Yes, Esperanto word order is fairly flexible, but some orders sound more neutral than others.

The most neutral order here is:

• Tiu regulo ne estas universala.

You could also say:

• Universala tiu regulo ne estas.

But that sounds more marked or emphatic, somewhat like:

• Universal, that rule is not.

For learners, it is best to stick with the normal order:

• subject + ne
  • verb + complement

So:

• Tiu regulo ne estas universala.

Yes. Estas is the present-tense form of esti (to be), and it is the same for all persons.

Examples:

• Mi estas = I am
• Vi estas = you are
• Li estas = he is
• Ŝi estas = she is
• Ĝi estas = it is
• Ni estas = we are
• Ili estas = they are

So Esperanto does not change the verb the way English does.

That makes this part simple:

• estas = is/are/am, depending on the subject

Tiu is pronounced roughly like TEE-oo, but as two vowels flowing together in one word.

A helpful breakdown:

• ti sounds like tee
• u sounds like oo

So:

• tiu ≈ TEE-oo

Also remember:

• Esperanto stress is usually on the second-to-last syllable
• ti-u has stress on ti

So the stressed pronunciation is roughly:

• TEE-oo

A rough English-friendly pronunciation is:

TEE-oo reh-GOO-lo neh ES-tahs oo-nee-vehr-SAH-lah

A more detailed breakdown:

• Tiu = TEE-oo
• regulo = reh-GOO-lo
• ne = neh
• estas = ES-tahs
• universala = oo-nee-vehr-SAH-lah

Stress:

• TI-u
• re-GU-lo
• NE
• ES-tas
• u-ni-ver-SA-la

Yes, that is a very natural interpretation of ne estas universala.

Literally, it means:

• is not universal

Depending on context, that can imply:

• it does not apply in all cases
• it is not valid everywhere
• it is not always true
• it is not a universal rule

So if the meaning has already been given to the learner, it is useful to know that universala can be understood both literally and more broadly, depending on context.

It is understandable, but it is not the normal way to say it.

The standard and natural form is:

• Tiu regulo ne estas universala.

Placing ne before estas is the usual way to negate the statement.

Using:

• estas ne universala

can sound awkward or overly influenced by English word order.

So learners should prefer:

• ne estas

rather than:

• estas ne