Kennarinn segir að „borða“ sé sagnorð.

The -inn is the suffixed definite article in Icelandic. So:

• kennari = teacher
• kennarinn = the teacher

Unlike English, Icelandic usually attaches the to the end of the noun rather than putting it in front as a separate word.

So in this sentence:

• Kennarinn = the teacher

Segir is the present-tense form meaning says.

The verb is að segja = to say.
Its present-tense forms include:

• ég segi = I say
• þú segir = you say
• hann/hún/það segir = he/she/it says

Since kennarinn is singular and means the teacher, Icelandic uses the 3rd person singular form:

• Kennarinn segir = The teacher says

Here að means that and introduces a subordinate clause:

• Kennarinn segir að ... = The teacher says that ...

This is different from the að used before an infinitive, where it often means to, as in:

• að borða = to eat

So Icelandic að can have different jobs depending on the sentence:

• segir að ... = says that ...
• að borða = to eat

Sé is the present subjunctive form of vera (to be).
Er is the normal present indicative form.

So:

• er = is
• sé = be / is, in subjunctive use

In a sentence like this, Icelandic often uses the subjunctive in a clause after segja að when reporting what someone says, thinks, claims, or presents as a statement. So:

• Kennarinn segir að borða sé sagnorð.

This is a very natural way to say:

• The teacher says that borða is a verb.

For an English speaker, the important point is that Icelandic uses the subjunctive much more visibly than modern English does.

Not always in every possible context, but it is very common here and is the standard form in this kind of reported statement.

A useful learner rule is:

• after verbs like segja, halda, telja, vilja, etc., Icelandic often uses the subjunctive in the subordinate clause, especially when reporting content rather than stating a plain fact directly.

So in this sentence, sé is exactly what many learners should expect.

Because the sentence is talking about the word itself, not about someone eating.

Here borða is being mentioned as a language item: the verb eat / to eat. When you talk about a verb as a word, Icelandic commonly uses its infinitive form.

So:

• borða = the verb form eat / to eat
• sé sagnorð = is a verb

In other words, the sentence is not saying that someone eats. It is classifying borða as a verb.

Good question. In Icelandic, the infinitive is often introduced by að, especially when it functions as to + verb:

• að borða = to eat

But when a word is being cited or discussed as a dictionary/grammar form, Icelandic often just uses the bare infinitive:

• borða

So here borða is being treated as the name of the verb. That is why the sentence can say:

• borða sé sagnorð = borða is a verb

You may still see að borða in other contexts, but here the bare form is very natural.

Sagnorð means verb.

It is the Icelandic grammar term for the part of speech. So:

• nafnorð = noun
• lýsingarorð = adjective
• sagnorð = verb

Therefore:

• borða sé sagnorð = borða is a verb

That is the normal structure of the subordinate clause.

Inside the clause introduced by að, the subject is the word being discussed:

• borða = the thing being talked about
• sé = is
• sagnorð = a verb

So the clause works like:

• [borða] [sé] [sagnorð]
• [borða] [is] [a verb]

This is a straightforward subject–verb–complement structure.

Icelandic has no indefinite article equivalent to English a/an.

So:

• sagnorð can mean verb or a verb, depending on context.

That means:

• borða sé sagnorð literally looks like borða is verb
• but in natural English it is borða is a verb

This is very common in Icelandic. You often have to supply a/an when translating into English.

Not really in normal interpretation. Because borða here is clearly being mentioned as a word, especially with the quotation marks. That tells you the sentence is about the form borða itself, not the action of eating.

So the meaning is about grammar terminology:

• The teacher says that borða is a verb.

Without that “mentioning the word” context, an English speaker might wonder whether it refers to the action, but the quotation marks remove that ambiguity.

Yes. They help show that borða is being mentioned as a word rather than used normally.

Compare:

• using a word: someone borðar = someone eats
• mentioning a word: borða is a verb

In grammar explanations, quotation marks, italics, or bold are often used for this purpose. In this sentence, they signal: “we are talking about the word borða itself.”

It is in the nominative, because it is a predicate noun after sé.

The clause is essentially:

• borða = subject
• sé = linking verb
• sagnorð = predicate noun

In Icelandic, predicate nouns after vera are normally nominative. So sagnorð stays in its basic dictionary form here.