Det jag vill ha till frukost i dag är en smörgås med skinka och en kopp te med honung.

Here det means what / that which in the pattern det ... som or det ... [clause].

So:

• Det jag vill ha = What I want
• literally: That which I want

The whole subject of the sentence is Det jag vill ha till frukost i dag = What I want for breakfast today.

This is very common in Swedish:

• Det jag behöver är vila. = What I need is rest.
• Det hon säger är sant. = What she says is true.

So this det is not the ordinary it.

Because vilja means to want, but in Swedish you often use vilja ha when talking about wanting to have or wanting to eat/drink/get something.

• Jag vill = I want
• Jag vill ha = I want / I want to have

In food contexts, vill ha is especially natural:

• Jag vill ha kaffe. = I want coffee.
• Vad vill du ha till lunch? = What do you want for lunch?

So Det jag vill ha till frukost is literally What I want to have for breakfast.

Yes. In this kind of expression, till often corresponds to English for.

• till frukost = for breakfast
• till lunch = for lunch
• till middag = for dinner

Examples:

• Vad äter du till frukost? = What do you eat for breakfast?
• Vi hade soppa till lunch. = We had soup for lunch.

English speakers often expect för, but till is the normal choice here.

Yes, both i dag and idag are used.

• i dag
• idag

They both mean today. The two-word spelling is often taught clearly to learners because it shows the structure:

• i = in/on
• dag = day

But in modern Swedish, idag is also very common.

The sentence is built like this:

• Det jag vill ha till frukost i dag = subject phrase
• är = verb
• en smörgås med skinka och en kopp te med honung = complement

So the pattern is:

• What I want for breakfast today
  • is
    • a ham sandwich and a cup of tea with honey

Inside the first part:

• Det = what/that which
• jag = I
• vill ha = want
• till frukost = for breakfast
• i dag = today

This kind of long subject is completely normal in Swedish.

Because both smörgås and kopp are en-words in Swedish.

Swedish nouns have two grammatical genders:

• en words
• ett words

So:

• en smörgås = a sandwich
• en kopp = a cup

You have to learn the noun together with its article:

• en smörgås
• en kopp
• ett te is possible when talking about a tea in some contexts, but here the structure is en kopp te = a cup of tea

A useful habit is to memorize nouns with en or ett, not by themselves.

En kopp te is the normal Swedish way to say a cup of tea.

This is a very common pattern:

• en kopp kaffe = a cup of coffee
• ett glas vatten = a glass of water
• en flaska vin = a bottle of wine

Swedish often puts the container noun first and then the substance directly after it, without a word like of.

You can say en kopp med te in some contexts, but that sounds more like a cup containing tea. In ordinary speech about food and drink, en kopp te is the natural choice.

Because te here is an uncountable substance noun, like tea in English.

So Swedish says:

• en kopp te = a cup of tea
• not normally en kopp ett te

Similarly:

• ett glas mjölk = a glass of milk
• en kopp kaffe = a cup of coffee

The article belongs to kopp, not to te.

Because med means with, and it is describing two different things:

• en smörgås med skinka = a sandwich with ham
• en kopp te med honung = a cup of tea with honey

So the first med modifies smörgås, and the second med modifies te.

This repetition is normal and helpful because it keeps the structure clear.

Because skinka and honung are being used as general food substances here, not as individually counted items.

• med skinka = with ham
• med honung = with honey

This is similar to English, where we also usually say:

• a sandwich with ham
• tea with honey

You would use an article only in more specific situations, for example if you were referring to a particular ham or a particular honey.

Not always exactly. Smörgås often gets translated as sandwich, but it can also mean an open sandwich or simply a slice of bread with toppings, depending on context.

In everyday learner translation, sandwich is usually fine. But culturally, Swedish smörgås can be a bit broader than English sandwich.

So in this sentence, en smörgås med skinka is best understood as a ham sandwich or a sandwich with ham, even though the Swedish word may cover slightly more than the English one.

Yes, you could say:

• Det som jag vill ha till frukost i dag är ...

This also means What I want for breakfast today is ...

The version without som is very common and natural:

• Det jag vill ha ...

The version with som is also grammatical, but often feels a little heavier or more explicit. In everyday Swedish, omitting som in this structure is very common.

The main verb of the whole sentence is är = is.

Even though you also see vill ha, that verb belongs inside the clause det jag vill ha till frukost i dag.

So:

• jag vill ha = the verb inside the what I want part
• är = the main verb that connects the subject to the thing wanted

This is similar to English:

• What I want for breakfast today is a sandwich and a cup of tea.

Yes, but the meaning or emphasis may change a little.

The given sentence is very natural if you want to present the whole idea as What I want for breakfast today is ...

A simpler version would be:

• Jag vill ha en smörgås med skinka och en kopp te med honung till frukost i dag.

That means essentially the same thing, but it sounds more like a direct statement: I want a ham sandwich and a cup of tea with honey for breakfast today.

So:

• Det jag vill ha ... är ... = more focus on what it is
• Jag vill ha ... = more direct and straightforward

A few words that English speakers often find tricky are:

• frukost — roughly FROO-kost
• smörgås — roughly SMUHR-gohs
• skinka — roughly SHIN-ka
• kopp — short vowel, like kopp with a clipped o
• honung — roughly HOO-nung

A few pronunciation notes:

• ö in smörgås does not exist in English; it is somewhat similar to the vowel in British bird, but not identical.
• sk before front vowels often becomes a sh-like sound, so skinka begins with something like sh.
• Swedish vowels are very sensitive to length, so short vs. long vowels matter a lot.

If you want, I can also break the whole sentence down into a word-by-word pronunciation guide.