Strikkeprøven viser strikkefastheten.

In Norwegian, the is usually attached to the end of the noun instead of standing as a separate word.

• strikkeprøve = a gauge swatch / a knitting sample

• strikkeprøven = the gauge swatch

• strikkefasthet = gauge / tension
• strikkefastheten = the gauge / the tension

So this sentence has two definite nouns.

A small detail:

• prøve ends in -e, so the definite ending is just -n: prøve → prøven
• fasthet takes -en in the definite form: fasthet → fastheten

Strikkeprøven is the definite form of strikkeprøve, a compound noun:

• strikke = knit / knitting
• prøve = sample, test, trial

In knitting, a strikkeprøve is the small sample piece you knit to check whether your stitches match the required gauge.

So strikkeprøven means the gauge swatch or the knitting sample.

Strikkefastheten is the definite form of strikkefasthet, another compound noun:

• strikke = knitting
• fasthet = firmness, tightness, consistency

In knitting language, strikkefasthet is the standard Norwegian word for gauge or sometimes tension.

So in this sentence, strikkefastheten means the gauge: the stitch density that the swatch shows.

The suffix -het often works a bit like English -ness. It turns an adjective or quality into a noun.

For example:

• fast = firm, fixed, tight
• fasthet = firmness, fixedness, tightness

So if you look at the word literally, strikkefasthet is something like knitting firmness/tightness. In actual knitting usage, though, it means gauge.

Because Norwegian usually writes compound nouns as one word.

So:

• strikke + prøve → strikkeprøve
• strikke + fasthet → strikkefasthet

This is very common in Norwegian. English often uses two words where Norwegian uses one compound word.

Writing them separately would usually look wrong in standard Norwegian.

Viser is the present tense of å vise, which means to show.

So:

• å vise = to show
• viser = show / shows / is showing

Norwegian verbs do not change for person the way English does.

So you get:

• jeg viser = I show
• du viser = you show
• han viser = he shows
• de viser = they show

The verb form stays viser for all of them.

This is the normal word order for a simple main clause:

• subject: strikkeprøven
• verb: viser
• object: strikkefastheten

So it follows the basic pattern subject + verb + object.

It also fits the Norwegian V2 rule: in main clauses, the finite verb is in the second position.

If you move something else to the front, the verb still stays second:

• Vanligvis viser strikkeprøven strikkefastheten.

Yes, but it changes the feel of the sentence.

• Strikkeprøven viser strikkefastheten sounds like you are talking about a specific swatch and the specific gauge it shows.
• En strikkeprøve viser strikkefasthet sounds more general, like a general statement about what a swatch does.

So the original sentence is more definite and context-specific.

Because both words are compounds connected to knitting.

• strikkeprøve = knitting sample / gauge swatch
• strikkefasthet = knitting gauge

The strikke- part is not a special grammar marker here. It is simply the first part of each compound and tells you that both nouns belong to the knitting context.

A rough pronunciation guide:

• strikkeprøven → STRIK-ke-prø-ven
• viser → VEE-ser
• strikkefastheten → STRIK-ke-fast-he-ten

The hardest sound for English speakers is usually ø in prøven.

A useful approximation:

• it is somewhat like the vowel in British English bird, but with rounded lips

There is no perfect English equivalent, so approximation is normal at first.

Stress usually falls on the first part of these compounds:

• STRIK-ke-prø-ven
• STRIK-ke-fast-he-ten