Esiliina on likainen.

Olla is the dictionary form, meaning to be.

In an actual sentence, Finnish verbs are usually conjugated.
On is the 3rd person singular form of olla, so it means is.

So:

• olla = to be
• on = is

Because esiliina is singular, Finnish uses on.

Finnish does not have articles like English a/an or the.

So esiliina can mean:

• an apron
• the apron
• sometimes just apron in a general sense

You understand which one is meant from the context, not from a separate article word.

This is very normal in Finnish.

It is in the nominative singular, which is the basic dictionary form.

In this sentence, esiliina is the subject:

• Esiliina = the apron / an apron
• on = is
• likainen = dirty

Since the subject is just being described, the basic nominative form is used.

Likainen is also in the nominative singular, because it describes the singular subject esiliina.

In Finnish, adjectives usually agree with the noun they describe in number and often in case.

Here both are singular and nominative:

• esiliina = nominative singular
• likainen = nominative singular

So the match is exactly what you would expect.

It changes.

Likainen is one of the common Finnish adjectives ending in -nen, and those words change quite a lot when inflected.

For example:

• nominative: likainen
• genitive: likaisen
• partitive: likaista

So in this sentence, likainen is just the basic nominative form because the sentence structure requires that form.

Yes. This is the most neutral and natural word order.

A very common Finnish sentence pattern is:

subject + verb + adjective/noun

So:

• Esiliina = subject
• on = verb
• likainen = description

That gives the plain statement: The apron is dirty.

Yes, Finnish word order is somewhat flexible, but changing it usually changes the emphasis.

For example:

• Esiliina on likainen. = neutral statement
• Likainen on esiliina. = unusual, marked, emphasizing dirty
• Onko esiliina likainen? = Is the apron dirty?

So the original sentence is the best neutral version.

Not exactly.

• Esiliina on likainen. = The apron is dirty.
  This is a full sentence.

• Likainen esiliina = a dirty apron / the dirty apron
  This is just a noun phrase, not a full sentence.

So Finnish works like English here:

• dirty apron ≠ the apron is dirty

A helpful rough pronunciation is:

eh-see-lee-nah

A few useful points:

• Finnish stress is almost always on the first syllable: ESIliina
• each vowel is pronounced clearly
• ii is a long i sound, so liina has a long vowel in the middle

Finnish spelling is very regular, so once you know the sound system, pronunciation becomes quite predictable.

Here, no. The -a is just part of the word itself.

The basic form is esiliina. It is not an added ending in this sentence beyond the normal dictionary form.

Many Finnish nouns happen to end in -a or -ä, so that alone does not tell you the case.

It would be:

Esiliinat ovat likaiset.

That means The aprons are dirty.

Notice all the changes:

• esiliina → esiliinat = aprons
• on → ovat = are
• likainen → likaiset = dirty, plural

This is a good example of agreement in Finnish: subject, verb, and adjective all reflect the plural.

You would say:

Esiliina ei ole likainen.

That means The apron is not dirty.

A few important things happen here:

• Finnish uses a special negative verb: ei
• the main verb changes from on to ole

So:

• on = is
• ei ole = is not

This is a very common Finnish pattern.

Yes. It is a basic copula sentence, where something is identified or described using olla (to be).

The pattern is:

X on Y
= X is Y

In this case, Y is an adjective describing a condition or state:

• Esiliina on likainen.
• literally: Apron is dirty.
• natural English: The apron is dirty.

This is one of the most common and useful Finnish sentence patterns.