Straffen er streng.

Because straffen is the definite form.

• straff = punishment
• en straff = a punishment
• straffen = the punishment

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

Norwegian usually puts the onto the noun as an ending.

So instead of a separate word, you often get:

• en straff = a punishment
• straffen = the punishment

A separate word such as den is used in some other structures, especially when an adjective comes before a definite noun:

• den strenge straffen = the severe punishment

So in Straffen er streng, the the is already built into straffen.

Er means is.

It is the present tense of å være, which means to be.

A few useful forms are:

• å være = to be
• er = is / am / are in the present tense

So:

• Straffen er streng = The punishment is severe / strict

Because streng is agreeing with a singular common-gender noun in a predicate position, after er.

Here is the pattern:

• common gender singular: streng
• neuter singular: strengt
• plural: strenge

Compare:

• Straffen er streng = The punishment is severe
• Regimet er strengt = The regime is strict
• Reglene er strenge = The rules are strict

A useful thing to notice: after er, the adjective agrees with gender and number, but not in the same way as when it stands directly before a noun.

Yes.

In Straffen er streng, streng comes after er, so it is a predicate adjective.

If you put the adjective directly before the noun, it becomes an attributive adjective, and the form changes:

• den strenge straffen = the severe punishment

So compare:

• Straffen er streng = The punishment is severe
• den strenge straffen = the severe punishment

This is a very common difference in Norwegian.

It can mean all of those, depending on context.

For a person, streng often means strict:

• En streng lærer = A strict teacher

For a punishment, streng often feels more like severe or harsh in natural English:

• Straffen er streng = The punishment is severe / harsh

So strict is not wrong as a dictionary meaning, but severe is often the most natural translation in this sentence.

A rough guide is:

• Straffen ≈ STRAH-fen
• er ≈ air or a lighter reduced sound, depending on dialect
• streng ≈ streng, with ng like the end of sing

A few pronunciation notes:

• Straffen has stress on the first syllable.
• The double ff shows that the vowel before it is short.
• In streng, the ng is pronounced as one sound, like English ng in sing. The g is not pronounced separately.

Pronunciation varies across Norway, but this will help you recognize the word.

This is the normal word order for a simple statement:

• Straffen = subject
• er = verb
• streng = adjective complement

So it follows the basic pattern:

subject + verb + complement

However, Norwegian main clauses follow the verb-second rule. That means if you move something else to the front, the verb still stays in second position:

• I dag er straffen streng = Today, the punishment is severe

So the sentence is simple, but it also fits an important general rule in Norwegian grammar.