Pitkospuut ovat märät.

Pitkospuut is a noun, and it is the plural form of pitkospuu.

It refers to the wooden planks or narrow wooden walkway laid over wet or marshy ground, especially in forests or bogs. In English, it is often translated as duckboards, boardwalk planks, or simply a boardwalk, depending on context.

Even though English might use a singular word like boardwalk, Finnish often uses the plural pitkospuut for this kind of structure.

Because pitkospuut is plural.

In Finnish, the verb olla (to be) changes according to whether the subject is singular or plural:

• on = is
• ovat = are

So:

• Pitkospuu on märkä. = one board / one plank walkway is wet.
• Pitkospuut ovat märät. = the duckboards / planks are wet.

Because both words are plural here.

• pitkospuut = plural noun
• märät = plural adjective

In Finnish, when an adjective describes a plural noun in this kind of sentence, it usually agrees with the noun in number. So if the noun is plural, the adjective is plural too.

That is why you get:

• pitkospuut = the duckboards
• märät = wet

Märät is the nominative plural form of the adjective märkä (wet).

The basic forms are:

• märkä = wet, singular
• märät = wet, plural

So:

• Polku on märkä. = The path is wet.
• Pitkospuut ovat märät. = The duckboards are wet.

You may also notice that the word changes internally, not just by adding -t. Finnish adjectives often do that when they are inflected.

Because Finnish does not form this plural by simply adding -t to the end of the dictionary form.

The adjective märkä changes stem when inflected:

• märkä → märät

This is a normal kind of pattern in Finnish. Many words change a little inside when they take endings.

So märkät is not a correct Finnish form.

Both pitkospuut and märät are in the nominative plural.

• pitkospuut is the subject of the sentence
• märät is the predicate adjective after ovat

In simple sentences of the type X are Y, Finnish often uses the nominative for both the plural subject and the predicate adjective:

• Talon seinät ovat valkoiset.
• Pitkospuut ovat märät.

Because märkiä is a different form: it is the partitive plural.

In this sentence, Finnish is making a straightforward statement that the duckboards are wet, so märät is the natural form.

Compare:

• Pitkospuut ovat märät. = The duckboards are wet.
• Näen märkiä pitkosuita. = I see wet duckboards.

In the second type of sentence, the grammar is different, so the adjective can appear in a different form.

Very often, yes.

Here the adjective märät agrees with pitkospuut in number:

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

For example:

• Ovi on märkä. = The door is wet.
• Ovet ovat märät. = The doors are wet.

Agreement is a very important part of Finnish grammar.

Yes:

• Pitkospuu on märkä.

That would mean the duckboard / plank is wet in the singular.

However, in real usage, pitkospuut is very common because this kind of walkway is naturally thought of as a set of planks rather than a single item.

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

So pitkospuut can mean:

• duckboards
• the duckboards

Which one sounds best in English depends on context.

The same is true for many Finnish nouns. You understand definiteness from the situation, not from an article.

The normal, neutral word order here is:

• Pitkospuut ovat märät.

That is the most natural way to say it.

Finnish word order is more flexible than English, so other orders are possible for emphasis or style, but this basic subject–verb–predicate order is what learners should use first.

A rough guide is:

• pit-kos-puut
• o-vat
• mä-rät

A few useful pronunciation points:

• uu in puut is a long vowel
• ä is a front vowel, not the same as English a
• Finnish stress usually falls on the first syllable: PIT-kos-puut, O-vat, MÄ-rät

Also, Finnish spelling is very regular, so once you know the sounds, pronunciation is usually predictable.

Yes. Finnish uses compound words very often, and pitkospuut comes from the singular compound pitkospuu.

The sentence therefore contains:

• one compound noun: pitkospuut
• one verb: ovat
• one adjective: märät

Recognizing compounds is very useful in Finnish, because many everyday nouns are built this way.