Textíllinn er notaður.

Because Icelandic usually puts the at the end of the noun instead of using a separate word.

• textíll = textile / fabric
• textíllinn = the textile / the fabric

Here, -inn is the masculine singular nominative form of the definite article. So the noun itself carries the meaning of the.

Er means is.

It is the 3rd person singular present tense of the verb að vera = to be.

So:

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

In this sentence, textíllinn is singular, so er is the correct form.

Notaður is the past participle of að nota, which means to use.

In a sentence like this, it works much like an adjective after er:

• að nota = to use
• notaður = used

So er notaður means is used.

Because notaður has to agree with textíllinn in gender, number, and case.

Textíll is a masculine singular noun, and here it is the subject, so it is in the nominative. That is why the matching form is notaður.

Compare:

• masculine singular: notaður
• feminine singular: notuð
• neuter singular: notað

For example:

• Bókin er notuð. = The book is used.
  (bók is feminine)
• Húsið er notað. = The house is used.
  (hús is neuter)

Yes, it can be understood as a passive-style sentence: The textile is used.

The structure is:

• subject + vera + past participle

So:

• Textíllinn er notaður.

This is a very common way to express something like English is used.

Depending on context, Icelandic vera + past participle can sometimes sound a bit like:

• a true passive: is used
• or a state/result: is in a used state

In many simple contexts, English speakers can just think of it as is used.

Because notaður is not directly modifying the noun inside the noun phrase here. It is a predicate adjective/predicate participle after the verb er.

Compare these two ideas:

• notaður textíll = used textile
  Here, notaður comes before the noun.
• textíllinn er notaður = the textile is used
  Here, notaður comes after er.

So the position changes depending on whether the word is:

• directly describing the noun, or
• linked to it through to be

The basic order here is:

• Subject + Verb + Complement

So:

• Textíllinn = subject
• er = verb
• notaður = complement

This looks very similar to English: The textile is used.

More broadly, Icelandic is often described as a verb-second language in main clauses, but in a simple statement like this, the word order feels very familiar to an English speaker.

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

That is also why the definite article appears in the form -inn, and why the participle appears in the matching nominative masculine singular form notaður.

So the sentence shows agreement between:

• textíllinn = masculine singular nominative
• notaður = masculine singular nominative

Yes, grammatically you could.

• Textíll er notaður = Textile is used / Fabric is used
• Textíllinn er notaður = The textile is used

Without the definite article, the sentence sounds more general or indefinite. With -inn, it refers to a specific textile/fabric.

So the difference is roughly like English a/the, though usage is not always identical in every context.

A rough English-friendly pronunciation is:

• Textíllinn ≈ TEKS-teel-lin
• er ≈ ehr
• notaður ≈ NO-ta-thur

A few helpful notes:

• í is a long ee sound.
• ð is like the th in this, not the th in thin.
• The final r is pronounced, unlike in many varieties of English.

This is only an approximation, but it is a useful starting point.

It most directly means textile, but depending on context, English translations such as fabric, cloth, or textile material may all be possible.

That is common when learning vocabulary: one Icelandic word may overlap with several English words, and the best translation depends on the situation.

So in a real text, textíllinn might refer to:

• a textile material
• a fabric
• a cloth item
• the textile industry’s product, depending on context

The dictionary forms are:

• textíll = textile / fabric
• að vera = to be
• að nota = to use

The sentence uses inflected forms:

• textíllinn = definite form of textíll
• er = present singular of vera
• notaður = past participle of nota, agreeing with textíllinn

This is a very typical Icelandic pattern: you learn the dictionary form, but in real sentences the forms change to show grammar.