Rengjøringsplanen starter robotstøvsugeren.

Because Norwegian very often makes compound nouns by joining words together.

• rengjøringsplanen = rengjøring
  • plan
    • -en
      • rengjøring = cleaning
      • plan = plan / schedule
      • -en = the
• robotstøvsugeren = robot
  • støvsuger
    • -en
      • robot = robot
      • støvsuger = vacuum cleaner
      • -en = the

So instead of writing something like cleaning plan the, Norwegian packs it all into one word: rengjøringsplanen = the cleaning schedule.

In Norwegian, the definite article is usually added as a suffix to the noun.

For example:

• en plan = a plan

• planen = the plan

• en støvsuger = a vacuum cleaner
• støvsugeren = the vacuum cleaner

That is why you see:

• rengjøringsplanen = the cleaning schedule
• robotstøvsugeren = the robot vacuum

This is one of the biggest differences from English.

That -s- is a very common linking sound/letter in Norwegian compounds.

So:

• rengjøring
  • plan becomes rengjøringsplan

This -s- does not always appear in every compound, but it is very common and often just has to be learned with the word. It helps the compound sound more natural.

Here starter means starts or turns on / activates.

The verb å starte can be used:

• intransitively: something starts
  
  • Møtet starter klokka åtte. = The meeting starts at eight.
• transitively: someone or something starts something else
  
  • Han starter bilen. = He starts the car.

In your sentence, it is transitive:

• Rengjøringsplanen starter robotstøvsugeren.
• The cleaning schedule starts the robot vacuum.

So the schedule is treated as the thing that triggers the vacuum to begin.

This is normal subject–verb–object word order, just like basic English.

• Rengjøringsplanen = subject
• starter = verb
• robotstøvsugeren = object

So literally:

• The cleaning schedule
  • starts
    • the robot vacuum

This is the most straightforward Norwegian sentence structure in a main clause.

You know mainly from word order and meaning.

In a normal Norwegian main clause:

• the subject usually comes before the verb
• the object usually comes after the verb

So here:

• Rengjøringsplanen comes before starter, so it is the subject
• robotstøvsugeren comes after starter, so it is the object

Also, semantically it makes sense that the schedule is what triggers the vacuum.

Yes, both are treated as masculine singular definite nouns here.

• en plan → planen
• en støvsuger → støvsugeren

When these nouns appear as the last part of a compound, that final noun determines the gender and the definite ending:

• rengjøringsplan is based on plan → rengjøringsplanen
• robotstøvsuger is based on støvsuger → robotstøvsugeren

So both end in -en because both head nouns are masculine singular in the definite form.

Grammatically, that would change the meaning and sound unnatural in most contexts.

Without the definite endings, you would get something more like:

• a cleaning schedule starts a robot vacuum

That is usually not what is meant here. The sentence you were given refers to a specific schedule and a specific robot vacuum, so the definite forms are natural:

• rengjøringsplanen = the cleaning schedule
• robotstøvsugeren = the robot vacuum

Yes, it is a normal and transparent compound word.

• robot = robot
• støvsuger = vacuum cleaner

So robotstøvsuger means robot vacuum or robot vacuum cleaner.

Norwegian often forms practical words this way, by combining existing nouns into one compound.

The sentence is understandable and grammatically fine. It sounds like something you might see in an instruction manual, app interface, or product description.

Depending on context, a speaker might also say something like:

• Rengjøringsplanen setter i gang robotstøvsugeren.
• Rengjøringsplanen starter opp robotstøvsugeren.

These can sound a little more explicitly like activates or sets in motion, but starter is perfectly natural.

Yes. starter is the present tense of å starte.

• å starte = to start
• starter = starts / is starting

For many Norwegian verbs, the present tense ends in -er:

• å snakke → snakker
• å jobbe → jobber
• å starte → starter

So this sentence is in the present tense: The cleaning schedule starts the robot vacuum.

Either can work, depending on context.

• plan often means plan
• but in practical everyday use, especially with devices and automation, schedule can be a very natural translation

So if this is about a robot vacuum running automatically at certain times, the cleaning schedule is probably the most natural English meaning. If the emphasis is more on a general plan, the cleaning plan is also possible.