Uttrykket er vanlig.

Because Norwegian usually puts the definite article at the end of the noun.

• et uttrykk = an expression / a phrase
• uttrykket = the expression / the phrase

So -et is the definite ending here. English uses a separate word (the), but Norwegian often attaches that meaning to the noun itself.

The base form is uttrykk.

Its forms are:

• et uttrykk = an expression
• uttrykket = the expression
• uttrykk = expressions
• uttrykkene = the expressions

So in this sentence, uttrykket is the definite singular form.

Uttrykk is a neuter noun in Bokmål, so it takes:

• et in the indefinite singular: et uttrykk
• -et in the definite singular: uttrykket

That is why you do not say en uttrykk.

Er means is / am / are. It is the present tense of å være (to be).

So:

• jeg er = I am
• du er = you are
• han er = he is
• uttrykket er vanlig = the expression is common

Norwegian uses er for all persons in the present tense, which is simpler than English.

Because in Norwegian Bokmål, adjectives ending in -ig usually do not add -t in the neuter singular.

So you get:

• en vanlig bil = a common/usual car
• et vanlig uttrykk = a common/usual expression
• uttrykket er vanlig = the expression is common

This is different from Swedish, where you would often see vanligt.

Vanlig usually means common, usual, or ordinary, depending on context.

In Uttrykket er vanlig, the most natural meaning is:

• The expression is common
• or The expression is usual

If the context is about language, common is probably the best translation.

No, this sentence has very straightforward word order:

• Uttrykket = subject
• er = verb
• vanlig = predicate adjective

So it follows the same basic pattern as English:

• The expression
  • is
    • common

However, it is useful to remember that Norwegian is generally a V2 language, which means the finite verb often comes second in main clauses.

Because vanlige is used in other situations, such as plural or definite adjective phrases.

Compare:

• et vanlig uttrykk = a common expression
• vanlige uttrykk = common expressions
• det vanlige uttrykket = the common expression
• uttrykket er vanlig = the expression is common

In your sentence, vanlig is being used predicatively after er, so vanlig is correct.

Not always. Uttrykk can mean several related things, depending on context:

• a wording or phrase
• an expression in language
• sometimes even an expression in a broader sense, like style or manner of expression

But in a sentence like Uttrykket er vanlig, a learner will usually understand it as the phrase/expression is common.

A rough learner-friendly pronunciation would be something like:

• UT-tryk-keh er VAHN-li

A few helpful points:

• y in uttrykket is not like English y. It is a rounded vowel, somewhat like German ü.
• kk is a strong k sound.
• In many pronunciations, the g in vanlig is weak or barely heard, so it can sound a bit like vanli.

You do not need perfect pronunciation right away, but uttrykk and the y sound are worth practicing.

Yes, very naturally.

Both are correct, but they are used a little differently:

• Uttrykket er vanlig. = The expression is common.
  This sounds like the expression has already been mentioned.

• Dette er et vanlig uttrykk. = This is a common expression.
  This is often used when introducing the expression for the first time.

So the sentence you have is perfectly fine, especially if the expression is already known from context.