Learn Hardcore Norwegian: Ordboken forklarer også vanskelige ord i naturfag og samfunnsfag. - The dictionary also explains difficult words in science and social studies.

So Ordboken means “The dictionary”, which fits this sentence because we’re talking about a specific dictionary (for example, the one being described in a textbook or on a website), not dictionaries in general.

If you wanted to talk about dictionaries in general, you could say:

En ordbok forklarer … = A dictionary explains …
Ordbøker forklarer … = Dictionaries explain …

Why ordboken and not ordboka? Are both correct?

Both forms are correct in Bokmål:

ordboken – more “bookish”, often seen as the neutral/standard written form
ordboka – more informal / speech-like, but still fully standard Bokmål

They are just two allowed definite forms of the same feminine noun ordbok. Many feminine nouns in Bokmål have this type of double option:

boken / boka (the book)
jenta / jenten (the girl; here jenten is a bit old‑fashioned)

So Ordboken forklarer … and Ordboka forklarer … mean exactly the same thing. Choice is about style and personal preference.

What tense is forklarer, and does it mean “explains” or “is explaining”?

Forklarer is the present tense of å forklare (to explain).

Norwegian present tense covers both English simple present and present continuous:

Ordboken forklarer vanskelige ord …
= “The dictionary explains difficult words …”
= “The dictionary is explaining difficult words …”

Context decides how you translate it, but the Norwegian form is the same. In a general statement like this, English usually uses “explains”.

Why is også placed after forklarer and not at the beginning, like Også ordboken forklarer …?

In a normal main clause with a regular subject first, Norwegian word order is:

Subject – finite verb – (sentence adverb like også) – rest

So:

Ordboken forklarer også vanskelige ord …
Subject = Ordboken
Finite verb = forklarer
Sentence adverb = også

Placing også here is the most neutral and common.

Other positions are possible but change the focus:

Også ordboken forklarer vanskelige ord …
= “The dictionary too explains difficult words …”
Emphasis is on the dictionary, maybe in contrast to something else.
Ordboken også forklarer vanskelige ord …
Sounds odd in standard Norwegian; sentence adverbs like også don’t usually go there in main clauses.

So the original placement is the standard pattern.

Could også go at the end: Ordboken forklarer vanskelige ord også?

It can, but the meaning/focus shifts slightly.

Ordboken forklarer også vanskelige ord …
= It also explains difficult words (as well as other kinds of words).
Ordboken forklarer vanskelige ord også …
= It explains difficult words as well (in addition to something else we just mentioned, like “easy words” or “foreign words”).

The second version sounds more like you are adding “difficult words” as an afterthought to a list. The original is the most natural neutral sentence.

Why is it vanskelige and not vanskelig?

Because ord here is plural (“words”), and adjectives in Norwegian agree with the number (and definiteness) of the noun.

With vanskelig (difficult):

et vanskelig ord = a difficult word (singular, neuter, indefinite)
to vanskelige ord = two difficult words (plural, indefinite)
de vanskelige ordene = the difficult words (plural, definite)

In the sentence, we have (flere) vanskelige ord — “(several) difficult words”, so the correct plural form is vanskelige.

But ord looks singular. How do I know it is plural here?

Ord is one of those Norwegian nouns where the singular and plural indefinite forms look the same:

et ord = a word (singular, indefinite)
ord = words (plural, indefinite)
ordet = the word (singular, definite)
ordene = the words (plural, definite)

Because of that, you often need context or adjectives to see if it’s singular or plural. Here the adjective gives it away:

vanskelig ord would suggest singular (“difficult word”)
vanskelige ord is clearly plural (“difficult words”)

So vanskelige ord = “difficult words”.

What exactly are naturfag and samfunnsfag?

They are names of school subjects / fields:

naturfag
- literally: nature + subject
- roughly = (natural) science, basic science in school (often includes biology, physics, chemistry, etc.)
samfunnsfag
- literally: society + subject
- roughly = social studies / social science (at school level)

They are compound nouns:
natur + fag, samfunn + fag, where fag means “subject” or “field (of study)”.

Why don’t naturfag and samfunnsfag start with a capital letter, even though they are school subjects?

In Norwegian, names of school subjects, fields of study, days of the week, and languages are not capitalized (unless they start a sentence):

naturfag, samfunnsfag, norsk, engelsk, matematikk, historie

This is different from English, where we normally write:

science, Social Studies, Norwegian, English, Math, History

So the lowercase naturfag and samfunnsfag are correct and standard.

Why is the preposition i (“in”) used with these subjects: i naturfag og samfunnsfag?

Using i + subject name is a very common way to say “in the subject of / in the field of” in Norwegian:

i naturfag = in (the subject of) science
i samfunnsfag = in (the subject of) social studies
i matematikk = in math
i historie = in history

So vanskelige ord i naturfag og samfunnsfag means “difficult words that appear in the subjects science and social studies.”

You could also use innen (for) in some contexts, but i is the simplest and most neutral.

Why isn’t there another i before samfunnsfag? Could I say i naturfag og i samfunnsfag?

Both are grammatically correct:

i naturfag og samfunnsfag
i naturfag og i samfunnsfag

In the original, i is understood to apply to both nouns:

i (naturfag og samfunnsfag)

This is very natural and not ambiguous.

If you repeat i:

i naturfag og i samfunnsfag

it sounds a bit more formal or emphatic, as if you’re stressing that it is true in both subjects separately. But the basic meaning is the same. The shorter version is more typical in everyday language.