Merkipenninn er svartur.

It is merkipenni + -inn.

• merkipenni = marker pen / felt-tip pen
• -inn = the (the definite article, attached to the end)

So merkipenninn means the marker.

In Icelandic, the definite article is very often added to the end of the noun as a suffix.

So:

• merkipenni = a marker / marker
• merkipenninn = the marker

This is one of the first big differences from English. Icelandic can use a separate word for definiteness in some contexts, but in simple sentences like this, the suffixed article is the normal choice.

Er is the present tense, 3rd person singular form of að vera (to be).

So:

• ég er = I am
• þú ert = you are
• hann / hún / það er = he / she / it is

Since merkipenninn is a singular thing, Icelandic uses er: the marker is.

Because Icelandic adjectives agree with the noun they describe in gender, number, and case.

Here, merkipenninn is:

• masculine
• singular
• nominative

So the adjective also has to be masculine singular nominative:

• masculine: svartur
• feminine: svört
• neuter: svart

That is why the sentence uses svartur.

You usually learn the gender as part of the noun’s basic form. The noun merkipenni is masculine.

A very common clue is the ending -i, which many masculine nouns have, though this is not a perfect rule for every noun in Icelandic.

Because merkipenni is masculine, both the article and the adjective follow masculine patterns:

• merkipenninn
• svartur

The dictionary forms are:

• merkipenni = marker
• að vera = to be
• svartur = black

So when looking words up, you would usually not search for merkipenninn, but for merkipenni. And you would not search for er, but for að vera.

Here svartur is a predicate adjective, not an adjective directly attached to the noun.

The structure is:

• Merkipenninn = subject
• er = verb
• svartur = description after to be

So the sentence literally works like:

• The marker is black.

If you wanted to say the black marker, then the adjective would go with the noun instead:

• svarti merkipenninn = the black marker

So these are two different structures:

• Merkipenninn er svartur. = The marker is black.
• Svarti merkipenninn ... = The black marker ...

It is in the nominative case, because it is the subject of the sentence.

In a sentence with að vera (to be), the subject is typically nominative, and the predicate adjective also matches it. So both the noun phrase and svartur are in nominative here.

That is why you get:

• merkipenninn — nominative singular definite
• svartur — nominative singular masculine

The verb er would stay the same if the subject is singular, but the adjective would change to match the noun’s gender.

For example:

• masculine: Merkipenninn er svartur.
• feminine: Bókin er svört. = The book is black.
• neuter: Borðið er svart. = The table is black.

So the important thing to notice is that black changes form in Icelandic.

A rough English-friendly guide would be:

• Merkipenninn ≈ MERK-ee-pen-nin
• er ≈ ehr
• svartur ≈ SVAR-tur

A few useful notes:

• r is usually trilled or tapped
• nn in Icelandic has a distinctive pronunciation that may not sound exactly like English nn
• stress usually falls on the first syllable of Icelandic words

So the main stress pattern is:

• MER-kipenninn
• ER
• SVAR-tur

Yes, but Merkipenninn er svartur is the normal, straightforward order.

It follows the basic pattern:

• Subject + Verb + Complement

Icelandic can sometimes move elements around for emphasis or style, but for a simple beginner sentence, this is the standard and most natural order.

So if you are learning, this is the pattern to remember first:

• X er Y = X is Y