Barna må tie.

Barna is the definite plural form of barn.

The noun pattern is:

• et barn = a child
• barnet = the child
• barn = children
• barna = the children

So in this sentence, barna refers to specific children, not children in general.

Because in Norwegian, the definite article is usually attached to the end of the noun.

So:

• barn = children
• barna = the children

That means barna already contains the idea of the.

A separate definite word is normally used when there is an adjective:

• de stille barna = the quiet children

But by itself, barna is enough.

Because tie is the infinitive form, and after må you normally use the infinitive.

So:

• barna må tie = the children must be quiet
• barna tier = the children are being quiet / keep quiet

In your sentence, må is the finite verb, so the next verb stays in the infinitive: tie.

After modal verbs like må, Norwegian uses the bare infinitive, without å.

Common modal verbs that work this way include:

• må
• kan
• skal
• vil
• bør

So you say:

• barna må tie

not:

• barna må å tie

Må is a modal verb. It expresses necessity, obligation, or strong requirement.

In English, it often matches:

• must
• have to

So grammatically, må is the verb that carries tense in the sentence, and tie depends on it.

The order is:

subject + finite verb + infinitive

So here:

• Barna = subject
• må = finite verb
• tie = infinitive

This also fits the normal Norwegian V2 pattern in main clauses: the finite verb tends to come in the second position.

For example:

• Barna må tie
• Nå må barna tie

In both cases, må stays in the second position.

Tie is pronounced as two syllables, roughly TEE-eh.

It is not pronounced like the English word tie.

A rough guide:

• ti sounds like English tea
• the final e is heard, giving a second syllable

So the whole word is something like TEE-eh.

Må is roughly pronounced like moh with a long vowel.

The letter å is an important Norwegian vowel. For many English speakers, a useful approximation is something between the vowel in law and a long o sound, depending on accent and dialect.

So må should not sound like ma.

Yes, but the meaning changes.

• Barna må tie = the children must be quiet
• Barn må tie = children must be quiet / children in general must be quiet

So barna refers to a specific group, while barn is more general or indefinite.

Grammatically, it is a statement:

• The children must be quiet

But in real use, it can function very much like a command, especially if a parent, teacher, or other authority says it.

So the form is declarative, but the effect can be directive.