Jeg smører et knekkebrød med ost når jeg ikke har tid til å lage mat.

Å smøre literally means to spread or to butter, but in everyday Norwegian it is also used more broadly for preparing a slice of bread or crispbread with a topping.

So Jeg smører et knekkebrød med ost is idiomatic Norwegian, even though a very literal English translation might sound odd. In natural English, you would often say I have a crispbread with cheese or I make myself a crispbread with cheese.

Because knekkebrød is a neuter noun in Norwegian. Neuter nouns take et in the indefinite singular.

So:

• et knekkebrød = a crispbread
• knekkebrødet = the crispbread

This is something you just have to learn with the noun: en, ei, or et.

Knekkebrød is a kind of dry, crisp flatbread that is very common in Norway. In English, crispbread is usually the best translation.

It is not quite the same as ordinary bread, and it is not exactly the same as a cracker either. It is its own very common food item in Scandinavia.

This is a good example of languages organizing the same idea differently.

In Norwegian, smøre noe med noe is a normal pattern:

• smøre brødskiva med smør
• smøre et knekkebrød med ost

English often prefers something like put cheese on a crispbread rather than spread a crispbread with cheese, especially if the cheese is sliced rather than spreadable.

So the Norwegian is natural, even if the most literal English version sounds a bit unusual.

Because ost here is being used as an uncountable mass noun, like cheese in English.

So:

• med ost = with cheese

If you said en ost, that would usually mean a cheese as a whole item or a type of cheese in a countable sense, not just cheese as food in general.

Here når means when or whenever. It is used for something that happens regularly or is expected to happen.

So this sentence means something like:

• Whenever I don’t have time to cook, I make myself a crispbread with cheese.

By contrast, hvis means if and sounds more conditional or hypothetical.

Compare:

• Når jeg ikke har tid, ... = when/whenever I don’t have time...
• Hvis jeg ikke har tid, ... = if I don’t have time...

In this sentence, når fits best because it describes a usual habit.

Because this is a subordinate clause, and in Norwegian subordinate clauses, ikke usually comes before the finite verb.

So:

• Jeg har ikke tid. = main clause
• når jeg ikke har tid = subordinate clause

This is an important word order rule in Norwegian:

• main clause: verb usually comes before ikke
• subordinate clause: ikke usually comes before the verb

This is a fixed and very common structure:

• ha tid til å + infinitive

It means to have time to do something.

So:

• jeg har tid til å lage mat = I have time to cook
• jeg har ikke tid til å lese = I don’t have time to read

The å is the infinitive marker, like to in English, and til belongs to the expression tid til å ...

Yes, literally it does, but idiomatically it usually means cook or prepare food.

So:

• å lage mat = to cook / to make food

It is a very common everyday phrase. If you want to be more specific, you can say things like:

• lage middag = make dinner
• lage frokost = make breakfast

Because Norwegian present tense is often used for habitual actions, just like English present simple.

So Jeg smører et knekkebrød med ost når jeg ikke har tid til å lage mat means this is something the speaker usually does in that situation.

It is not necessarily happening right this second; it describes a typical pattern.

Yes. The clause after når needs its own subject.

So Norwegian says:

• ... når jeg ikke har tid ...

You cannot leave out jeg just because the subject is the same as in the main clause. Norwegian normally requires an explicit subject in each clause.

Then the sentence becomes:

Når jeg ikke har tid til å lage mat, smører jeg et knekkebrød med ost.

When a subordinate clause comes first, the main clause still follows Norwegian word order rules, so the verb comes before the subject in the main clause:

• ..., smører jeg ...

Not:

• ..., jeg smører ...

This is a very common Norwegian pattern and an important part of V2 word order in main clauses.