Jag fryser in matresterna.

Here, fryser in is the present-tense form of the particle verb frysa in, which means to freeze something for storage, especially food.

So Jag fryser in matresterna means that the speaker is putting the leftovers in the freezer to save them for later.

The in is not just the ordinary preposition in. It is part of the verb expression frysa in.

Because frysa and frysa in do not mean exactly the same thing.

• frysa can mean to freeze or to be cold
• frysa in specifically means to freeze something and store it

So:

• Jag fryser = I am cold / I am freezing
• Jag fryser in matresterna = I’m freezing the leftovers

The little particle in changes the meaning in an important way.

Yes. Swedish frysa can be used in different ways depending on context.

• Jag fryser = I’m cold
• Vattnet fryser = The water is freezing
• Jag fryser in matresterna = I’m freezing the leftovers

So the same verb can refer to feeling cold, becoming frozen, or freezing something for storage when combined with in.

Because frysa in is a particle verb, and in a normal main clause Swedish often puts it like this:

subject + finite verb + particle + object

So:

• Jag fryser in matresterna

That word order is normal. The particle in belongs with the verb, but it appears after the conjugated verb form fryser.

You can think of it as similar to how English sometimes uses verbs with particles, although the details are different.

Because Swedish loves compound nouns.

matresterna is built from:

• mat = food
• rester = leftovers / remains
• -na = the definite plural ending

So matresterna means the leftovers or more literally the food leftovers.

In Swedish, compounds are normally written as one word, not two. So matresterna is correct, while mat resterna would be wrong.

The ending -na marks definite plural.

So:

• en matrest = a leftover
• matrester = leftovers
• matresterna = the leftovers

Unlike English, Swedish often puts the at the end of the noun instead of using a separate word.

Because matresterna refers to specific leftovers, probably the ones already known from the situation.

Compare:

• Jag fryser in matrester. = I freeze leftovers / I’m freezing some leftovers
• Jag fryser in matresterna. = I’m freezing the leftovers

So the definite form makes it sound like both speaker and listener know which leftovers are meant.

Grammatically, it might be understood, but it is less natural if you mean putting leftovers in the freezer.

Frysa in is the normal expression for freezing food for later use. Without in, the sentence can sound more like you are simply causing the leftovers to become frozen, rather than storing them in the freezer in the usual everyday sense.

So if you mean I’m freezing the leftovers to save them, Jag fryser in matresterna is the better choice.

Fryser is the present tense of frysa.

Basic forms are:

• infinitive: frysa in
• present: fryser in
• past: frös in
• supine: fryst in

So:

• Jag fryser in matresterna = I freeze / I am freezing the leftovers
• Jag frös in matresterna = I froze the leftovers
• Jag har fryst in matresterna = I have frozen the leftovers

It can mean both, depending on context.

Swedish does not have a separate mandatory form like English am freezing for an action happening right now. The present tense often covers both:

• I freeze the leftovers
• I am freezing the leftovers

In real life, this sentence will usually be understood from context. If someone says it while putting food into containers and opening the freezer, the meaning is clearly I am freezing the leftovers.