Flokken er stor.

Flokken is the definite singular form of flokk, so it means the flock rather than just a flock.

• en flokk = a flock
• flokken = the flock

In Norwegian, the definite article is often attached to the end of the noun instead of being a separate word.

Flokk is a masculine noun in Bokmål:

• en flokk
• flokken

Many Norwegian nouns are masculine, feminine, or neuter, and that affects how they are formed in the indefinite and definite forms.

Er is the present tense of the verb å være = to be.

So:

• flokken = the flock
• er = is
• stor = big / large

Together: The flock is big.

Unlike English, Norwegian verbs do not change depending on the subject:

• jeg er = I am
• du er = you are
• flokken er = the flock is

It is always er in the present tense.

Stor is the basic adjective form used with a singular common-gender noun here, and flokken is singular.

Compare:

• en stor flokk = a big flock
• flokken er stor = the flock is big
• et stort hus = a big house (neuter)
• store flokker = big flocks (plural)

So stor is correct because flokken is singular and not neuter.

It can mean either big or large, depending on context. In everyday English, big is usually the most natural translation, but large can also work.

So Flokken er stor could be understood as:

• The flock is big
• The flock is large

This is the normal Norwegian word order for a simple statement:

subject + verb + adjective

• Flokken = subject
• er = verb
• stor = adjective/predicate

This is very similar to English:

• The flock is big

Yes, if the context already makes it clear what it refers to.

• Flokken er stor. = The flock is big.
• Den er stor. = It is big.

Because flokk is a common-gender noun, the pronoun is den.

A rough guide for an English speaker:

• flokken ≈ FLOK-en
• er ≈ a short air or weak ehr, depending on dialect
• stor ≈ stoor with a Norwegian r

A few helpful notes:

• The o in flokken is short.
• The o in stor is longer.
• Norwegian pronunciation varies by dialect, especially for r and er.

It is singular.

• en flokk = a flock
• flokken = the flock
• flokker = flocks
• flokkene = the flocks

Even though a flock contains many animals or birds, the noun itself is grammatically singular here.

No. Flokk is a general word for a group or flock, especially of animals, birds, or even people in some contexts.

Examples:

• en saueflokk = a flock of sheep
• en fugleflokk = a flock of birds
• en flokk mennesker = a group of people

So the exact kind of flock depends on context.

Yes. If the subject noun were neuter singular, the adjective would usually take -t in this kind of sentence.

Compare:

• Flokken er stor. = common gender singular
• Huset er stort. = neuter singular (The house is big)

So adjective agreement matters in Norwegian.

Yes, but it means something slightly different: That flock is big or That particular flock is big.

Compare:

• Flokken er stor. = The flock is big
• Den flokken er stor. = That flock is big

Adding den makes it more specific or contrastive.