Jeg presser sitron over fisken før vi spiser.

In Norwegian, foods and ingredients are often used without an article when you mean the substance rather than one whole item. Here, sitron is understood as lemon/lemon juice in a general sense.

So:

• Jeg presser sitron over fisken = I squeeze lemon over the fish
• Jeg presser en sitron over fisken = I squeeze a whole lemon over the fish

Both can be possible, but the version without an article sounds more like you are talking about the ingredient, not counting lemons as objects.

Because fisken is the definite singular form, meaning the fish.

• fisk = fish / a fish / fish in general
• fisken = the fish

In this sentence, the speaker means a specific fish, probably the one they are about to eat, so fisken is the natural choice.

The noun fisk is a masculine noun, so its definite singular form is made by adding -en:

• en fisk = a fish
• fisken = the fish

This is very common in Norwegian. Instead of putting a separate word in front, Norwegian often marks definiteness at the end of the noun.

Here presser means squeezes/presses, especially to get juice out of something like a lemon.

The base form is å presse.

It is related to English press, but in this food context English usually says squeeze. So although the verbs are related, the most natural English translation here is usually squeeze, not press.

Usually, presser is the better choice here.

• å presse is natural when you press or squeeze something to get liquid out
• å klemme often means to squeeze physically, grip tightly, or hug

So for lemon over fish, presser is the idiomatic verb. Klemmer would sound less natural in this context.

Over fits the image of squeezing lemon from above so that it falls over/onto the fish.

In this kind of sentence, over often means something like over and onto the surface of something.

So over fisken is natural with actions like:

• helle something over something
• strø something over something
• presse something over something

You may also hear på fisken in some contexts, but over fisken works very well when the action is coming from above.

Because før introduces a subordinate clause.

In Norwegian subordinate clauses, the normal order is:

subject + verb

So:

• før vi spiser = before we eat

The order spiser vi is used in main clauses or questions, not after før in a subordinate clause.

Norwegian often uses the present tense for actions in the near future or for things that are expected to happen next.

That is very similar to English:

• before we eat
• when we leave
• after she arrives

So før vi spiser is completely normal, even though the eating happens after the lemon-squeezing.

Not necessarily. The object can be left out when it is obvious from context.

So før vi spiser simply means before we eat, and listeners will naturally understand what is meant from the situation.

If you want to be more explicit, you could say:

• før vi spiser fisken
• før vi spiser den

But the shorter version is perfectly normal.

Here it is a conjunction, because it is followed by a full clause:

• før vi spiser

A full clause has a subject and a verb: vi spiser.

Compare that with a prepositional use:

• før middag = before dinner

So:

• før + clause → conjunction
• før + noun phrase → preposition

The dictionary, or infinitive, forms are:

• å presse
• å spise

In the sentence, they appear in the present tense:

• jeg presser = I squeeze
• vi spiser = we eat

This is useful to remember because Norwegian dictionaries normally list verbs under the infinitive form with å.

Yes. You could say:

Før vi spiser, presser jeg sitron over fisken.

That is also correct.

When a subordinate clause comes first in Norwegian, the verb in the main clause usually comes before the subject:

• Før vi spiser, presser jeg ...

Not:

• Før vi spiser, jeg presser ...

That is a very important Norwegian word-order pattern.