Ullarteppið er á svefnloftinu.

The ending -ið is the definite article attached to the noun. Icelandic usually says the by adding it to the end of the word instead of using a separate word like English does.

So:

• ullarteppi = a wool blanket
• ullarteppið = the wool blanket

In this sentence, ullarteppið is also in the nominative singular, because it is the subject of the sentence.

The base or dictionary form is ullarteppi.

It is a neuter noun. That matters because Icelandic noun endings change depending on:

• gender
• number
• case
• whether the noun is definite or indefinite

Here, ullarteppið is:

• neuter
• singular
• nominative
• definite

Yes. Ullarteppi is a compound noun:

• ull = wool
• teppi = blanket, carpet, rug

So ullarteppi literally means something like wool-blanket or wool rug, depending on context.

Compound nouns are extremely common in Icelandic, much like in German.

Er is the 3rd person singular present tense of að vera, which means to be.

Because the subject ullarteppið is singular, the verb is singular too:

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

So Ullarteppið er ... means The wool blanket is ...

Because it is:

• definite = the sleeping loft
• singular
• dative

The base noun is svefnloft. In this sentence, after á with a location meaning, the noun goes into the dative, and the definite article is added as part of the ending.

So:

• svefnloft = sleeping loft
• svefnloftinu = in/on the sleeping loft

For learners, the important thing is that -inu here reflects both case and the.

The preposition á can take either accusative or dative, depending on the meaning.

A very useful rule is:

• dative = location, being somewhere
• accusative = movement toward a place

In this sentence, the blanket is already located there, so Icelandic uses dative:

• á svefnloftinu = on/in the sleeping loft

If the sentence described movement to that place, Icelandic would normally use the accusative instead.

This is a very common learner question. Icelandic á often literally means on, but with places it does not always match English one-to-one.

With something like svefnloft (a sleeping loft), Icelandic naturally uses á, because a loft is often thought of as an upper platform or area. In English, though, we may say either:

• on the sleeping loft
• in the sleeping loft

depending on how we imagine the space.

So the Icelandic preposition is natural even if English chooses a different one.

Yes. It is made from:

• svefn = sleep
• loft = loft, attic, upper room/space

So svefnloft means sleeping loft.

Like ullarteppi, it is a compound noun. Learning to spot compounds is very helpful in Icelandic, because many long words become easier once you break them into parts.

This is the normal, straightforward Icelandic word order for a simple statement:

• subject: Ullarteppið
• verb: er
• place phrase: á svefnloftinu

So it follows the familiar pattern:

Subject + Verb + Location

That said, Icelandic word order is more flexible than English. You could also move the location phrase to the front for emphasis, for example:

• Á svefnloftinu er ullarteppið.

That sounds more marked or stylistically different, but it is grammatical.

Because Icelandic usually expresses the by attaching it to the noun itself.

So instead of using a separate article like English:

• the wool blanket
• the sleeping loft

Icelandic normally says:

• ullarteppið
• svefnloftinu

This is one of the biggest structural differences from English. When learning Icelandic, it helps to think of the as something that is often built into the noun ending rather than standing alone.

A rough pronunciation guide for an English speaker is:

• Ullarteppið ≈ UHT-lar-tehp-pith
• er ≈ ehr
• á ≈ ow as in cow, but longer
• svefnloftinu ≈ SVEVN-lof-ti-nu

A few useful notes:

• ll in modern Icelandic often has a special pronunciation that may not sound like plain English ll
• ð in -ið is like the th in this
• stress usually falls on the first syllable of Icelandic words

So the whole sentence is stressed roughly like:

UHL-lar-tepp-ið er Á svefn-loft-inu

A native recording is still the best way to learn the exact sound.