Vitnið er hér.

The dictionary form is vitni.

In this sentence:

• vitni = witness / a witness
• vitnið = the witness

So Vitnið er hér. literally breaks down as:

• vitnið = the witness
• er = is
• hér = here

The -ð is the definite article, meaning the.

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

So:

• vitni = a witness or just witness
• vitnið = the witness

This is very common in Icelandic. Compare:

• hús = house
• húsið = the house

Because vitni already ends in a vowel, the definite ending here is just -ð.

Er means is.

It is the 3rd person singular present-tense form of the verb vera, which means to be.

A few useful forms are:

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

So in Vitnið er hér, er simply links the subject to its location: The witness is here.

Here vitnið is in the nominative singular definite.

Why?

• It is the subject of the sentence.
• Subjects are normally in the nominative in Icelandic.

One small detail: for this noun, the nominative and accusative singular look the same in form, but in this sentence its job is clearly that of the subject, so we analyze it as nominative.

Because grammatical gender and natural gender are not always the same thing.

In Icelandic, every noun belongs to a grammatical gender: masculine, feminine, or neuter. Vitni happens to be neuter, even though a witness in real life can be male or female.

So the noun behaves grammatically like a neuter noun:

• vitni = neuter noun
• vitnið = the definite neuter singular form

This is normal in Icelandic and not something you need to translate literally into English.

Because hér means here, in this place, while hingað means to here, indicating movement toward the speaker.

So:

• Vitnið er hér. = The witness is here.
  (location, no movement)
• Vitnið kemur hingað. = The witness is coming here.
  (movement toward here)

Since er describes where the witness is located, hér is the correct choice.

Yes.

Vitnið er hér. is the most neutral order: subject + verb + location.

But Icelandic can also say:

• Hér er vitnið.

That also means The witness is here or Here is the witness, but it gives more emphasis to here.

This happens because Icelandic often follows a verb-second pattern:

• if the subject comes first: Vitnið er hér
• if hér comes first, the verb still stays second: Hér er vitnið

So both are correct, but they are used with slightly different emphasis.

A rough English-friendly approximation is:

VIHT-nith er hyer

A few helpful notes:

• Stress in Icelandic is usually on the first syllable, so: VIT-nið
• The tn in vitni is not pronounced like smooth English tn; it has a breathy sound, something like htn
• The final ð in vitnið is often heard like th in thin at the end of a word
• hér is roughly like hyer, with an r that is usually tapped or trilled, not an English r

This is only an approximation, but it should help you recognize the sentence when you hear it.