Plantesprøyten øker luftfuktigheten.

Because Norwegian normally writes compound nouns as one word, where English often uses two words or a hyphenated form.

So:

• plante = plant
• sprøyte = sprayer / spray bottle / mister

Together, plantesprøyte means something like plant sprayer.

Then -n at the end makes it definite:

• en plantesprøyte = a plant sprayer
• plantesprøyten = the plant sprayer

This is very typical in Norwegian: compounds are usually written as a single word.

The ending -en marks the noun as definite singular: the plant sprayer.

In Norwegian, definite nouns usually take the article as a suffix instead of using a separate word like English the.

Compare:

• en sprøyte = a sprayer
• sprøyten = the sprayer

Since this is a compound noun, the definite ending goes on the whole compound:

• en plantesprøyte = a plant sprayer
• plantesprøyten = the plant sprayer

Sprøyte is often treated as a feminine noun, but in Bokmål many feminine nouns can also take the common-gender/masculine-style forms.

So both of these can be possible in Bokmål:

• ei sprøyte / sprøyta
• en sprøyte / sprøyten

In your sentence, the form used is plantesprøyten, which is completely normal Bokmål.

So -en does not automatically mean the noun is strictly masculine; it can also be a valid Bokmål form for many feminine nouns.

Øker is the present tense of å øke = to increase.

Examples:

• å øke = to increase
• øker = increases / is increasing
• økte = increased
• har økt = has increased

Norwegian verbs do not change according to the subject the way English verbs sometimes do.

So you get:

• Jeg øker
• Du øker
• Den øker
• Vi øker

Same form every time in the present tense: øker.

Luftfuktighet specifically means air humidity or humidity.

It is another compound noun:

• luft = air
• fuktighet = moisture / humidity

So:

• luftfuktighet = humidity
• luftfuktigheten = the humidity

You could say fuktigheten in some contexts, but that is broader and could refer to moisture in general, not specifically the humidity of the air. Using luftfuktigheten makes the meaning more precise.

For the same reason as plantesprøyten: it is in the definite singular form.

Compare:

• en luftfuktighet = a humidity level / a humidity
• luftfuktigheten = the humidity

In this sentence, Norwegian is talking about a specific humidity level, such as the humidity in a room, greenhouse, or around the plants.

So the structure is:

• Plantesprøyten = the subject
• øker = the verb
• luftfuktigheten = the object

This is a very common thing learners notice.

In English, we often say:

• It increases humidity

But Norwegian often prefers the definite form when referring to a specific, understood condition in a place:

• øker luftfuktigheten = literally increases the humidity

It sounds like the humidity in the relevant space is being increased.

So even if English uses no article, Norwegian may still use the definite form naturally.

The word order is the standard Norwegian pattern:

Subject + Verb + Object

• Plantesprøyten = subject
• øker = verb
• luftfuktigheten = object

So:

Plantesprøyten øker luftfuktigheten.

This is very similar to normal English word order.

One important Norwegian rule is that the verb usually stays in second position in main clauses. In this simple sentence, that happens automatically because the subject comes first.

The letter ø is a vowel that does not exist in standard English, so it can take some practice.

A rough guide:

• In øker, the ø is somewhat like the vowel in French peu or German schön
• In sprøyten, the øy is a diphthong, roughly moving from ø toward an i/y-like sound

Very approximate pronunciation help:

• øker ≈ UH-kerr, but with rounded lips
• sprøyten ≈ SPRØY-ten, where øy is one glide

Important: these are only rough approximations. The key is to round your lips more than you would for most English vowel sounds.

Yes. A compound like plantesprøyte can refer to a sprayer used for plants, and the exact type depends on context.

It might mean:

• a small spray bottle for misting plants
• a plant mister
• a sprayer used for watering or treatment

So the word gives you the general idea: something used to spray plants. The exact English translation may vary depending on the situation.

In many varieties of Bokmål, yes, that can be possible if you use the feminine form consistently.

For example:

• ei plantesprøyte = a plant sprayer
• plantesprøyta = the plant sprayer

Your sentence uses plantesprøyten, which is also correct and very common in Bokmål.

So both styles may exist, depending on the writer’s preference and the variety of Bokmål being used.