Eu gosto de iogurte com mel no café da manhã.

Because the verb gostar normally takes the preposition de in Portuguese.

• gostar de + noun → Eu gosto de iogurte.
• gostar de + verb → Eu gosto de cozinhar.

So even though English says I like yogurt, Portuguese says more literally I like of yogurt. You should learn gostar as gostar de, since the de is part of how the verb is used.

You can often omit Eu in Portuguese, because the verb form gosto already shows the subject is I.

So both are natural:

• Eu gosto de iogurte com mel no café da manhã.
• Gosto de iogurte com mel no café da manhã.

Including Eu can add emphasis, clarity, or contrast. In everyday Brazilian Portuguese, dropping the subject pronoun is very common when the meaning is clear.

In this sentence, iogurte and mel are being used in a general sense, not referring to one specific yogurt or one specific honey.

So:

• gosto de iogurte = I like yogurt / I like eating yogurt
• com mel = with honey

This is very natural when talking about foods in general.

If you were talking about something specific, you might use an article:

• Eu gosto do iogurte que você comprou. = I like the yogurt you bought.
• Usei o mel da sua avó. = I used your grandmother’s honey.

Com mel means with honey.

It describes how the yogurt is eaten: yogurt with honey.

So the structure is:

• iogurte = yogurt
• com mel = with honey

Together: iogurte com mel = yogurt with honey

No is a contraction of:

• em + o = no

Here, em means something like in/at, and o is the masculine singular article the.

So:

• no café da manhã = at breakfast / literally in the breakfast

This kind of contraction is extremely common in Portuguese:

• em + o = no
• em + a = na
• em + os = nos
• em + as = nas

Café da manhã is the standard expression for breakfast in Portuguese.

Literally, it means coffee of the morning:

• café = coffee
• da = de + a = of the
• manhã = morning

Even though it literally contains the word coffee, the full phrase means breakfast, not just the drink.

So:

• no café da manhã = at breakfast
• not simply in the morning

If you wanted to say in the morning, you would usually say:

• de manhã

Da is a contraction of:

• de + a = da

This happens because manhã is a feminine noun, so it uses the article a.

So:

• café da manhã = literally coffee of the morning

This is another very common contraction pattern in Portuguese:

• de + o = do
• de + a = da
• de + os = dos
• de + as = das

In this kind of sentence, it is often understood as at breakfast or for breakfast, depending on context.

• Eu gosto de iogurte com mel no café da manhã.

This most naturally means that yogurt with honey is something the speaker likes to eat at breakfast time.

A very similar sentence is:

• Eu gosto de comer iogurte com mel no café da manhã. = I like to eat yogurt with honey for breakfast.

So the idea is the same, even if the most literal translation may vary.

The sentence follows a very normal Portuguese word order:

• Eu = I
• gosto de = like
• iogurte com mel = yogurt with honey
• no café da manhã = at breakfast

So the structure is:

Subject + verb + preposition + thing liked + time/context

This word order sounds natural and neutral in Brazilian Portuguese.

In this sentence, native speakers will normally understand com mel as describing iogurte, not café da manhã.

So the intended reading is:

• iogurte com mel = yogurt with honey

not:

• breakfast with honey

The sentence naturally groups as:

[iogurte com mel] [no café da manhã]

In Brazilian Portuguese, iogurte is commonly pronounced approximately like:

• yo-GOOR-chee or yo-GOOR-tee, depending on accent

A few helpful points:

• io- sounds like yo-
• the stressed syllable is usually gur
• final te in many Brazilian accents can sound like chee or tee

So don’t pronounce it like English eye-oh-gurt. The beginning is more like yo.

Manhã can be tricky because of the nasal sound.

A rough approximation is:

• ma-NYAHN (with a nasal ending)

Important details:

• nh sounds like ny in canyon
• ã is nasal; it is not a plain a
• the stress is on the last syllable: -nhã

So it does not sound like English man-ha.

Yes. That is also correct and very natural.

• Eu gosto de iogurte com mel no café da manhã. = I like yogurt with honey at breakfast.

• Eu gosto de comer iogurte com mel no café da manhã. = I like to eat yogurt with honey at breakfast / for breakfast.

The version without comer is shorter and very common. The version with comer is a bit more explicit about the action of eating.

Yes, it probably would.

Your original sentence talks about yogurt in general:

• Eu gosto de iogurte com mel. = I like yogurt with honey.

If you mean a specific yogurt, you would often use an article:

• Eu gosto do iogurte com mel. = I like the yogurt with honey.

That happens because:

• de + o = do

So:

• gosto de iogurte = I like yogurt in general
• gosto do iogurte = I like the specific yogurt

This is an important difference in Portuguese.