Learn Hardcore Icelandic: Kennarinn notar sterka rödd í kennslustofunni. - The teacher uses a strong voice in the classroom.

The ending -inn is the masculine singular definite ending in the nominative case. So Kennarinn literally means “teacher-the,” which corresponds to “the teacher” in English.

What is the verb notar here, and how is it conjugated?

Notar is the 3rd person singular present tense of the verb að nota (to use).

Present tense of að nota:

ég nota – I use
þú notar – you (sg.) use
hann / hún / það notar – he / she / it uses
við notum – we use
þið notið – you (pl.) use
þeir / þær / þau nota – they use

So Kennarinn notar… = The teacher uses…

Why is it sterka rödd and not sterk rödd?

Because the adjective sterkur (strong) has to agree in case, gender, and number with the noun rödd (voice).

rödd is feminine singular and is the direct object of the verb, so it is in the accusative case.
Feminine singular accusative of sterkur is sterka.

Forms of sterkur (singular, key ones):

Feminine nominative: sterk
Feminine accusative/dative: sterka

If rödd were the subject in the nominative, you’d say sterk rödd (e.g. Sterk rödd heyrist – “A strong voice is heard”). As an object, it becomes sterka rödd.

How can I tell that rödd is feminine, and what are some of its forms?

You mainly learn the gender with the word, but there are some hints and patterns.

Rödd (voice) is feminine. Some important forms:

Nominative sg.: rödd – (a) voice
Accusative sg.: rödd – (a) voice (same spelling)
Dative sg.: rödd – to/for a voice (same spelling)
Genitive sg.: raddar – of a voice

The adjective and definite article (if present) usually show the case/gender more clearly than the noun itself in forms like this:

sterk rödd – strong voice (nom. fem.)
sterka rödd – strong voice (acc./dat. fem.)
sterka röddin – the strong voice (nom. fem.)
sterku röddina – the strong voice (acc. fem.)

In your sentence, sterka tells you rödd is not nominative.

Why is there no word for “a” in sterka rödd? In English we say “a strong voice”.

Icelandic has no indefinite article (no word for “a/an”). Indefiniteness is shown simply by the absence of a definite ending or article.

rödd = a voice
röddin = the voice

So:

sterka rödd = a strong voice
sterku röddina = the strong voice

Your sentence uses sterka rödd, so it means “a strong voice,” even though there is no separate word for “a”.

What exactly is going on in í kennslustofunni? Why that ending -unni?

Í is the preposition “in”, and it normally takes the dative when it means a static location (“in, inside”).

The noun is kennslustofa (classroom), a feminine noun:

Nominative sg.: kennslustofa – classroom
Dative sg. (indefinite): kennslustofu – (in) a classroom
Dative sg. (definite): kennslustofunni – (in) the classroom

So:

í kennslustofu = in a classroom
í kennslustofunni = in the classroom

The -unni ending is the feminine dative singular definite ending.

Why does í take the dative here? Could it also take the accusative?

Yes, í can take either dative or accusative, depending on meaning:

Í + dative → location (where?)
- í kennslustofunni = in the classroom (the teacher is there)
Í + accusative → movement into (where to?)
- Hann fer í kennslustofuna = He goes into the classroom

In your sentence, the teacher is already in the classroom, so í uses the dative: í kennslustofunni.

Can I change the word order, e.g. say Kennarinn notar í kennslustofunni sterka rödd?

You can move elements around, but some orders sound more natural than others.

The neutral, most natural order here is:
- Kennarinn notar sterka rödd í kennslustofunni.
Kennarinn notar í kennslustofunni sterka rödd. is grammatically correct, but sounds a bit marked or stylistically unusual; you’d typically only do this for special emphasis.

Basic Icelandic word order is Subject – Verb – (Object) – (Other complements/adjuncts), with flexibility for emphasis and rhythm.

Could I say Kennarinn notar háa rödd instead of sterka rödd? Does sterk mean “loud”?

Sterk rödd literally means “strong voice”, and it often implies that the voice is powerful / carrying / firm, which can overlap with “loud,” but not always.

sterk rödd – strong, powerful voice
há rödd / há rödd (acc.: háa rödd) – high(-pitched) voice
hávær rödd – loud voice
djúp rödd / djúpa rödd – deep voice

So if you want to emphasize loudness, hávær rödd is clearer. Sterk rödd is more about the strength and carrying power of the voice than pitch.

Can I make kennslustofa and rödd plural in a similar way?

Yes, and the patterns will help you with other nouns too.

Kennslustofa (f.) – classroom:

Nom. pl.: kennslustofur – classrooms
Dat. pl. (def.): í kennslustofunum – in the classrooms

Rödd (f.) – voice:

Nom. pl.: raddir – voices
Acc. pl.: raddir
Dat. pl.: röddum
Gen. pl.: radda

You’d then adjust the adjective and article:

sterkar raddir – strong voices (nom. pl.)
Kennarar nota sterkar raddir í kennslustofunum. – Teachers use strong voices in the classrooms.