Om pumpen fungerar, behöver du kanske ingen reservdel.

Pumpen is the definite form of pump, so it means the pump.

In Swedish, the definite article is often added to the end of the noun:

• en pump = a pump
• pumpen = the pump

So Om pumpen fungerar means If the pump works or If the pump is working.

Here, om means if.

It introduces a condition:

• Om pumpen fungerar ... = If the pump works ...

This is very common in Swedish for conditional sentences.

Do not confuse this with när, which usually means when.
So:

• Om pumpen fungerar = If the pump works
• När pumpen fungerar = When the pump works

Fungerar is the present tense of fungera, which means to function / to work.

So:

• fungera = infinitive, to work / to function
• fungerar = present tense, works / is working

In this sentence, Swedish uses the present tense just as English does in an if-clause:

• Om pumpen fungerar = If the pump works

Also, Swedish present tense often covers both English works and is working, depending on context.

This is because Swedish follows the V2 rule in main clauses. That means the finite verb usually comes in the second position.

The sentence starts with the subordinate clause:

• Om pumpen fungerar

After that, the main clause begins, and the finite verb comes first in that clause:

• behöver du kanske ingen reservdel

So the order becomes:

• Om pumpen fungerar, behöver du kanske ingen reservdel.

If you remove the first clause, you get normal word order:

• Du behöver kanske ingen reservdel.

So the inversion happens because the sentence begins with Om pumpen fungerar.

Kanske means maybe or perhaps.

In this sentence it comes after the subject in the main clause:

• behöver du kanske ingen reservdel

That is natural Swedish word order after inversion.

Compare:

• Du behöver kanske ingen reservdel.
• Om pumpen fungerar, behöver du kanske ingen reservdel.

So kanske is placed where sentence adverbs often go in Swedish: not at the very end, but before the object phrase.

Ingen means no or not any and is used directly before a noun.

Here:

• ingen reservdel = no spare part / not any spare part

This is different from inte, which usually negates verbs, adjectives, or whole clauses.

Compare:

• Du behöver ingen reservdel. = You need no spare part / You do not need any spare part.
• Du behöver inte en reservdel. = not the normal way to say this

So before a singular en-word noun, ingen is the natural choice.

Because reservdel is an en-word.

Swedish negative forms agree with the noun:

• ingen for singular en-words
• inget for singular ett-words
• inga for plurals

Examples:

• ingen reservdel = no spare part
• inget problem = no problem
• inga reservdelar = no spare parts

Since reservdel is en reservdel, the correct form is ingen reservdel.

Because Swedish normally writes compound nouns as a single word.

So:

• reserv
  • del = reservdel

This is very common in Swedish. English often writes these as two words, but Swedish usually joins them.

Other examples:

• biltvätt = car wash
• sommarhus = summer house
• vattenpump = water pump

A good habit in Swedish is to expect many noun combinations to be written as one word.

Not strictly. In modern Swedish, the comma after an introductory subordinate clause is often optional.

So both of these are acceptable:

• Om pumpen fungerar, behöver du kanske ingen reservdel.
• Om pumpen fungerar behöver du kanske ingen reservdel.

The comma can make the sentence easier to read, especially if the first clause is a bit longer.

It can mean either, depending on context.

Swedish has one simple present form here:

• pumpen fungerar

That can correspond to English:

• the pump works
• the pump is working

So Swedish does not need a separate progressive form like English is working in this kind of sentence.