In frigo c’è del salmone per cena, e nel cassetto tengo ancora un pacco di cracker.

Both can be correct, but in frigo is very common in everyday spoken Italian.

• in frigo = in the fridge
• nel frigo = also in the fridge

Why the difference?

• frigo is a shortened form of frigorifero
• With short everyday location words, Italian often drops the article in casual speech:
  • in frigo
  • in cucina
  • a letto

So in frigo c’è del salmone sounds very natural and conversational.

If you said nel frigorifero c’è del salmone, that would also be completely correct, just a little more explicit.

C’è means there is.

It is made of:

• ci = there
• è = is

So:

• c’è del salmone = there is some salmon

This is the singular form. If the noun were plural, you would use ci sono:

• c’è del salmone = there is some salmon
• ci sono dei cracker = there are some crackers

Del salmone means some salmon.

Here del is a partitive article, often used when talking about an unspecified quantity of something.

• del salmone = some salmon
• del pane = some bread
• del vino = some wine

If you just say c’è salmone, it can sound less natural in this context. Italian often prefers the partitive when referring to an unspecified amount of food.

So:

• c’è del salmone = there is some salmon

is the most natural choice here.

Del is a contraction of:

• di + il = del

In partitive use, this often corresponds to some in English.

Other common forms are:

• dello
• della
• dei
• degli
• delle

Examples:

• del formaggio = some cheese
• della pasta = some pasta
• dei biscotti = some cookies
• delle fragole = some strawberries

In your sentence, salmone is masculine singular, so del is the correct form.

They mean slightly different things.

• per cena = for dinner
• a cena = at dinner / for dinner depending on context

In this sentence, per cena emphasizes purpose:

• There is some salmon for dinner

It means the salmon is intended to be eaten at dinner.

Examples:

• Ho comprato il pane per cena = I bought bread for dinner
• A cena mangiamo presto = At dinner / For dinner we eat early

So per cena is a very natural choice when talking about what food is meant for the evening meal.

Because nel is the normal combination of:

• in + il = nel

So:

• nel cassetto = in the drawer

With cassetto, the article is normally kept. You would not usually say in cassetto.

Compare:

• in frigo = a common idiomatic everyday expression
• nel cassetto = standard structure with article

So the difference is mostly due to usage: frigo often behaves like a fixed everyday location phrase, while cassetto does not.

Here tengo means something like:

• I keep
• I still have
• I store

It comes from tenere.

In context:

• nel cassetto tengo ancora un pacco di cracker = in the drawer I still keep/have a pack of crackers

This is not exactly the same as basic ownership I have = ho, but in many situations it can overlap.

Compare:

• Ho un pacco di cracker = I have a pack of crackers
• Tengo un pacco di cracker nel cassetto = I keep a pack of crackers in the drawer

Using tenere gives more of a sense of keeping something somewhere.

Ancora means still here.

In Italian, adverbs like ancora often come before the part they modify. In this sentence it modifies the idea of I keep / I still have.

• tengo ancora un pacco di cracker = I still keep/have a pack of crackers

This placement is very natural.

You may also see adverbs in slightly different positions depending on emphasis, but this version is the standard, neutral one.

Un pacco di cracker means a pack / packet of crackers.

• pacco is a general word for a pack, package, or parcel
• In food contexts, it can mean a packet/box/package depending on the product

Yes, una confezione di cracker is also possible and often sounds a bit more specific or neutral for packaged food.

Roughly:

• un pacco di cracker = a pack of crackers
• una confezione di cracker = a package/pack of crackers

Both are fine. Un pacco is very common in everyday speech.

Because cracker is a borrowed word, and many borrowed nouns in Italian do not change form in the plural.

So you can have:

• un cracker
• due cracker
• un pacco di cracker

The word stays the same.

This is common with many foreign nouns in Italian, especially modern food terms and English loanwords.

Italian often puts a location first to set the scene.

So:

• In frigo c’è del salmone literally: In the fridge there is some salmon
• nel cassetto tengo ancora un pacco di cracker literally: In the drawer I still keep a pack of crackers

This word order is very natural in Italian. It helps organize information by starting with where something is.

English can do this too, but usually prefers:

• There’s some salmon in the fridge
• I still keep a pack of crackers in the drawer

Italian is more flexible with word order, especially when introducing location first.

Yes, absolutely.

• Nel cassetto tengo ancora un pacco di cracker
• Ho ancora un pacco di cracker nel cassetto

Both are correct, but they feel slightly different.

• tengo emphasizes that you keep/store it there
• ho simply states that you have it there

Also, putting nel cassetto first gives a slightly more descriptive or scene-setting tone.

So the original sentence sounds very natural, but your alternative is good too.

Yes, it sounds very natural and everyday.

A few things make it feel colloquial and normal:

• frigo instead of the full frigorifero
• in frigo as a common spoken expression
• tengo ancora in a practical, everyday sense
• food vocabulary like salmone and cracker

Nothing in the sentence is strange or overly formal. It sounds like something someone might casually say at home while talking about what food is available.