Cetere, la saŭco estas preta.

Cetere is a discourse word: it helps connect this sentence to what was said before. It often means something like besides, by the way, in addition, or moreover, depending on context.

It does not affect the grammar of the rest of the sentence very much. You can think of it as setting up the speaker’s next comment.

In this sentence, cetere is not the subject, object, or main verb. It is just an introductory adverb.

The comma shows that cetere is being used as an introductory word.

English often does the same thing with phrases like by the way or moreover:

• By the way, the sauce is ready.

In Esperanto, this comma is natural and helps readability, though punctuation can be a little flexible in real writing.

La is the definite article, meaning the.

So:

• saŭco = sauce
• la saŭco = the sauce

Esperanto has only one article, la, and it does not change for gender, number, or case.

Whether you use la depends on context. If both speaker and listener know which sauce is meant, la saŭco is natural. If you were talking about sauce in a more general or indefinite way, you might leave la out.

Saŭco is pronounced approximately like SOW-tso, where sow rhymes with cow.

A few useful points:

• aŭ is a diphthong, roughly like the ow sound in cow
• c in Esperanto is always pronounced ts, never like English k or s
• so saŭco breaks down roughly as saŭ-co = sow-tso

This makes Esperanto pronunciation much more regular than English spelling.

Estas is the present tense of esti, meaning to be.

So:

• mi estas = I am
• ĝi estas = it is
• la saŭco estas = the sauce is

Esperanto verbs do not change depending on the subject. The form estas stays the same whether the subject is I, you, he, she, it, we, or they.

Because preta is an adjective meaning ready.

In Esperanto:

• adjectives end in -a
• nouns end in -o
• adverbs end in -e
• verbs have endings like -as, -is, -os, etc.

So in la saŭco estas preta, the structure is:

• la saŭco = subject
• estas = linking verb
• preta = adjective describing the subject

This is like English the sauce is ready, where ready is an adjective, not a verb.

Because pret- is not being used as the main verb here.

Compare:

• La saŭco estas preta. = The sauce is ready.
• La saŭco pretas. = also possible, meaning roughly The sauce is ready.

In the first sentence, preta is an adjective used with estas. In the second, pretas treats pret- as a verb.

Both are possible in Esperanto, but estas preta may feel especially straightforward to a learner because it matches the pattern is ready.

There is no -n because there is no direct object here.

The sentence is built around to be:

• la saŭco is the subject
• preta is a predicate adjective describing the subject

Predicate adjectives after esti do not take -n in a normal sentence like this.

So:

• La saŭco estas preta. is correct
• La saŭcon estas preta is wrong, because that would mark sauce as a direct object

Because preta is agreeing with the subject in its basic form here: singular and not accusative.

Esperanto adjectives agree with the nouns they describe in number and case:

• singular noun → singular adjective
• plural noun → plural adjective
• accusative noun → accusative adjective

Here:

• la saŭco is singular
• it is not accusative
• so the adjective is also singular and not accusative: preta

If the subject were plural, you would get:

• La saŭcoj estas pretaj. = The sauces are ready.

Yes, Esperanto word order is fairly flexible, as long as the sentence stays clear.

The most neutral order is:

• Cetere, la saŭco estas preta.

But you could also see:

• La saŭco, cetere, estas preta.
• Preta estas la saŭco.
  This sounds more marked or stylistic.

Even though Esperanto allows flexibility, learners should usually start with the normal, clear order: subject + verb + complement.

Usually it describes the current state: the sauce is ready now.

Like English ready, preta often refers to a condition rather than a permanent characteristic. The grammar itself does not force a permanent-or-temporary distinction; context does that.

So in this sentence, the most natural interpretation is that the sauce has reached a ready state.

No. Esperanto has several connecting adverbs, and each has its own nuance.

For example:

• cetere = besides / by the way / moreover
• krome = in addition
• plie = furthermore
• parenteze = parenthetically / as an aside

A learner should not assume these are always interchangeable. Cetere often has a slightly conversational, side-note feel, though the exact nuance depends on context.

The sentence follows a very common Esperanto pattern:

introductory adverb + subject + esti + predicate adjective

So here:

• Cetere = introductory adverb
• la saŭco = subject
• estas = form of esti
• preta = predicate adjective

This pattern is extremely useful:

• La pordo estas fermita. = The door is closed.
• La kafo estas varma. = The coffee is hot.
• La infano estas laca. = The child is tired.

So this sentence is a good example of very standard Esperanto grammar.