La servo en tiu restoracio estas pli bona ol en alia kafejo.

La is the definite article, meaning the.

In Esperanto, you often use la when talking about a specific thing that both speaker and listener can identify. Here, la servo means the service at that particular restaurant, not service in general.

So:

• La servo en tiu restoracio = the service in that restaurant
• Servo en tiu restoracio would sound more like service in that restaurant as a general idea, which is less natural here.

Tiu is the demonstrative word used before a noun, meaning that.

• tiu restoracio = that restaurant

Tio means that thing and normally stands alone, without a noun after it.

Compare:

• tiu restoracio = that restaurant
• tio = that / that thing

So tio restoracio is not correct Esperanto.

This is the standard way to make a comparison in Esperanto:

• pli = more
• bona = good
• ol = than

So:

• pli bona ol = better than literally more good than

This is how Esperanto forms comparatives very regularly:

• granda = big
• pli granda = bigger
• interesa = interesting
• pli interesa = more interesting

And for equality or extremes:

• same bona kiel = as good as
• la plej bona = the best

Because bona is an adjective, and here it describes servo.

• servo = a noun
• bona = an adjective describing that noun

The structure is:

• La servo ... estas bona = The service is good

By contrast, bone is an adverb, meaning well, and it describes verbs, adjectives, or other adverbs.

Compare:

• La servo estas bona. = The service is good.
• La kelnero servas bone. = The waiter serves well.

So in your sentence, the subject is la servo, so the adjective bona is the right form.

Because neither word is a direct object here.

In Esperanto, the -n ending usually marks:

1. the direct object
2. movement toward something in some cases

Here, servo is the subject of the sentence, and bona is a predicate adjective after estas, so neither takes -n.

Breakdown:

• La servo = subject
• estas = is
• pli bona = predicate adjective phrase

So:

• La servo estas bona. = correct
• La servon estas bonan. = incorrect

Because both phrases mean in a place.

• en tiu restoracio = in that restaurant
• en alia kafejo = in another café

The sentence is comparing the service in one place with the service in another place.

Esperanto often repeats the preposition where English might also repeat it, though sometimes English can leave things more implicit. Here, repeating en is completely natural and clear.

Because Esperanto, like English, can leave out words that are understood from context.

The full idea is something like:

• La servo en tiu restoracio estas pli bona ol la servo en alia kafejo.

But repeating la servo is unnecessary, since the meaning is already clear. So the shorter version is more natural:

• La servo en tiu restoracio estas pli bona ol en alia kafejo.

English does the same kind of thing:

• The service in that restaurant is better than in another café.

Even if English speakers might sometimes prefer than the service in another café, the shorter version is still understandable, and Esperanto allows the same kind of omission.

Because alia kafejo means another café or some other café, not a specific café already identified.

• alia kafejo = another/other café
• la alia kafejo = the other café

So the sentence is probably making a general comparison with some other café, not one definite previously mentioned café.

Compare:

• en alia kafejo = in another café
• en la alia kafejo = in the other café

Both are possible in Esperanto, but they mean slightly different things.

Not in this sentence.

Pli bona is correct because the sentence is describing the noun servo.

• La servo estas pli bona = The service is better.

If you said pli bone, that would be an adverb, and it would usually describe how someone performs an action.

For example:

• La personaro servas pli bone. = The staff serves better.
• Oni manĝas pli bone tie. = One eats better there.

So:

• describing a noun: bona
• describing an action: bone

Esperanto word order is fairly flexible, but this sentence uses a very normal, straightforward order.

Basic structure:

• La servo — subject
• en tiu restoracio — phrase modifying servo
• estas — verb
• pli bona ol en alia kafejo — comparison

You could rearrange some parts for emphasis, but the original version is the most neutral and natural for learners.

For example, En tiu restoracio la servo estas pli bona ol en alia kafejo is also understandable, but the original sentence is simpler and stylistically plain.

Usually it is very close, but not always perfectly identical in every culture.

In Esperanto:

• kafejo literally comes from kafo
  • -ej-
• -ej- means place for
• so kafejo is basically a place for coffee, a café or coffeehouse

Likewise:

• restoracio = restaurant

So the sentence compares service in a restaurant with service in another café/coffeehouse. That is a normal and understandable contrast, even if the exact kind of business might vary a little depending on context.