Η βάρκα είναι μικρή.

No. Η here is the Greek capital letter eta, not the English H.

• In Modern Greek, Η / η is pronounced ee /i/.
• So Η βάρκα is pronounced roughly ee VAR-ka.
• English speakers often misread it as H, but in this sentence it is just the feminine singular definite article: the.

A natural pronunciation is:

ee VAR-ka EE-ne mee-KREE

More closely:

• Η = /i/
• βάρκα = /ˈvarka/
• είναι = /ˈine/
• μικρή = /miˈkri/

A few useful notes:

• β in Modern Greek sounds like v, not English b.
• ρ is a rolled or tapped r.
• The stress marks show which syllable gets the emphasis.

η is the feminine singular definite article, meaning the.

So:

• η βάρκα = the boat

If you wanted a boat, you would usually say:

• μια βάρκα = a boat

In this sentence, η is there because the noun is:

• singular
• feminine
• definite

Because Greek nouns have grammatical gender, and that does not have to match real-life sex.

So βάρκα is grammatically feminine simply because that is how the noun behaves in Greek.

You can often recognize feminine nouns by endings like:

• -α
• -η

Since βάρκα is feminine singular, the article is η and the adjective also has to be feminine singular:

• η βάρκα είναι μικρή

είναι is the verb to be in the present tense.

Here it means is:

• Η βάρκα είναι μικρή. = The boat is small.

A useful thing to know:

• είναι is used for both he/she/it is and they are

Examples:

• Η βάρκα είναι μικρή. = The boat is small.
• Οι βάρκες είναι μικρές. = The boats are small.

So Greek does not change this form between 3rd person singular and plural.

Because the adjective must agree with βάρκα.

Since βάρκα is:

• feminine
• singular
• nominative

the adjective also appears in the feminine singular nominative form:

• μικρή = small for a feminine singular noun

Compare:

• μικρός = masculine singular
• μικρή = feminine singular
• μικρό = neuter singular

So:

• ο κήπος είναι μικρός = the garden is small
• η βάρκα είναι μικρή = the boat is small
• το σπίτι είναι μικρό = the house is small

Both η βάρκα and μικρή are in the nominative.

Why?

• βάρκα is the subject of the sentence, so it is nominative.
• After είναι, the predicate adjective also agrees with the subject, so it is nominative too.

So the full grammar is:

• η = feminine singular nominative article
• βάρκα = feminine singular nominative noun
• μικρή = feminine singular nominative adjective

Because this sentence is using small as a predicate adjective, not as an adjective inside the noun phrase.

Compare:

• Η βάρκα είναι μικρή. = The boat is small.
• Η μικρή βάρκα. = The small boat.

So:

• η βάρκα = the boat
• είναι = is
• μικρή = small

In the sentence you gave, Greek is following the same basic idea as English:

• subject + is + adjective

Yes. Greek word order is more flexible than English, although Η βάρκα είναι μικρή is the most neutral and standard order.

You may also hear:

• Μικρή είναι η βάρκα.

That can sound more emphatic, something like:

• The boat is small
• or It’s the boat that is small

But for a learner, the safest default is:

• Η βάρκα είναι μικρή.

The accent marks show which syllable is stressed.

• βάρκα → stress on βάρ-
• είναι → stress on εί-
• μικρή → stress on -κρή

This is important because stress matters in Greek pronunciation.

Notice that η has no accent mark here because it is a monosyllabic unstressed article.

Because Greek does not need a dummy subject like English it in a sentence like this.

English says:

• It is small
• The boat is small

Greek can simply say:

• Είναι μικρή. = It is small / She is small (depending on context)
• Η βάρκα είναι μικρή. = The boat is small

Once the subject is stated, Greek does not need an extra it.

You would make the article, noun, and adjective plural:

• Οι βάρκες είναι μικρές. = The boats are small.

Changes:

• Η → Οι
• βάρκα → βάρκες
• μικρή → μικρές
• είναι stays the same

This is a good example of agreement in Greek:

• article + noun + adjective all change together
• the verb είναι does not change here