Skredderen måler sømmonnet.

Because skredderen is the definite singular form of skredder.

• skredder = a tailor
• skredderen = the tailor

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

This noun is a common gender noun in Bokmål, so the usual definite singular ending is -en.

Because sømmonn is a neuter noun, and -et is the usual definite singular ending for neuter nouns.

• et sømmonn = a seam allowance
• sømmonnet = the seam allowance

So the sentence uses definite forms for both nouns:

• Skredderen = the tailor
• sømmonnet = the seam allowance

Because Norwegian usually expresses definiteness by adding an ending to the noun.

English:

• the tailor
• the seam allowance

Norwegian:

• skredder-en
• sømmonn-et

This is one of the biggest differences from English. Norwegian can also use a separate determiner like den, det, or de, but usually that happens when there is an adjective:

• skredderen = the tailor
• den dyktige skredderen = the skilled tailor

Without an adjective, the ending by itself is normally enough.

Måler is the present tense of the verb å måle.

• å måle = to measure
• måler = measures / is measuring

In Norwegian, the present tense often ends in -r:

• snakker = speaks
• skriver = writes
• måler = measures

In a simple sentence like this, måler can correspond to either English measures or is measuring, depending on context.

No, this is the basic normal word order for a simple statement:

Subject + verb + object

• Skredderen = subject
• måler = verb
• sømmonnet = object

So it works very much like English:

• The tailor measures the seam allowance.

This is one of the easiest Norwegian sentence patterns for English speakers to recognize.

Yes. Sømmonn is a compound noun.

It is built from:

• søm = seam / sewing
• monn = allowance / margin / extra amount

Together, sømmonn means seam allowance.

A useful thing to know about Norwegian compounds is that the last part usually carries the grammatical ending. That is why the definite form is:

• sømmonnet

and not something like two separately marked words.

You would usually say:

En skredder måler et sømmonn.

That means A tailor measures a seam allowance.

Compare:

• Skredderen måler sømmonnet. = The tailor measures the seam allowance.
• En skredder måler et sømmonn. = A tailor measures a seam allowance.

So the main difference is:

• skredder → skredderen
• sømmonn → sømmonnet

A learner-friendly approximation is something like:

SKRED-er-en

A few points:

• sk before r is usually pronounced as a hard sk, not like English sh
• the dd does not mean you strongly pronounce both d sounds separately
• the final -en is an unstressed ending

The stress is mainly on the first syllable: SKRED-

Exact pronunciation can vary a bit by dialect, but that approximation is a good start.

A rough learner-friendly pronunciation is:

SUM-mon-ne

Important things to notice:

• ø is a vowel English does not really have; it is not the same as o
• mm and nn show that the preceding vowel is short
• the -et ending in natural speech is often reduced, so it may not sound like a full English et

Stress is usually on the first syllable: SØM-

If you are learning Bokmål pronunciation, it is best to listen to native audio because vowels like ø are hard to master from spelling alone.

Because in a normal statement, Norwegian uses a finite verb as the main verb of the sentence.

Here:

• Skredderen = subject
• måler = finite present-tense verb

The infinitive would be å måle, but that form is used in other structures, for example:

• Skredderen vil måle sømmonnet. = The tailor wants to measure the seam allowance.
• Det er viktig å måle sømmonnet. = It is important to measure the seam allowance.

So in this sentence, måler is the correct form because it is the main verb in the present tense.

Yes. Norwegian present tense often covers both:

• The tailor measures the seam allowance
• The tailor is measuring the seam allowance

Which meaning is intended depends on context.

If you want to make the ongoing action especially clear, Norwegian can also use other expressions, but the plain present tense is very common and natural.

Yes, that helps a lot.

Knowing the gender helps you form:

• the correct indefinite article
• the correct definite ending
• adjectives and pronouns later on

For these words:

• en skredder → skredderen
• et sømmonn → sømmonnet

A good habit is to learn nouns together with their article:

• en skredder
• et sømmonn

That makes it much easier to build correct sentences later.