asagohan ni yooguruto to ringo wo taberu to, kibun ga sukosi yoku narimasu.

Here, 朝ご飯に means for breakfast.

• 朝ご飯 = breakfast
• に marks the occasion or context of the meal

So the sentence is not saying eat breakfast as the object. Instead, it is saying that for breakfast, the speaker eats yogurt and apples.

Compare:

• 朝ご飯にヨーグルトを食べる = eat yogurt for breakfast
• 朝ご飯を食べる = eat breakfast

Because ヨーグルトとりんご are the things being eaten, they take を, and 朝ご飯 uses に instead.

Because ヨーグルト と りんご forms one combined noun phrase: yogurt and apples.

The particle と connects the two nouns, and the whole phrase becomes the object of 食べる.

So:

• ヨーグルトとりんごを食べる = eat yogurt and apples

You do not need:

• ヨーグルトをとりんごを食べる ✘

That would be unnatural.

That と means and.

It connects nouns in a complete list:

• ヨーグルトとりんご = yogurt and apples

This use of と is different from the later と after 食べる. Japanese uses the same word for multiple grammatical functions, so it is very common to see と twice in one sentence with different meanings.

This と is a conditional or result marker. In this sentence, it means something like:

• when
• if
• whenever

So:

• 食べると、気分が少しよくなります = when I eat them, I feel a little better = if I eat them, I feel a little better = whenever I eat them, my mood improves a little

This と often expresses a natural result, repeated result, or something that regularly happens.

In this sentence, it sounds like a habitual pattern: When I eat yogurt and apples for breakfast, I feel a little better.

Before this conditional と, Japanese normally uses the plain form.

So you say:

• 食べると = when/if someone eats

not:

• 食べますと ✘ in normal modern speech

Even though the sentence ends politely with なります, the verb before と stays in plain form. This mix is completely normal:

• 食べると、気分がよくなります。

Because 気分 is the thing that becomes better.

• 気分 = mood / feeling
• が marks the subject of よくなります

So the structure is basically:

• 気分がよくなる = one’s mood gets better / one feels better

In English, we often say I feel better, but Japanese often phrases it as my mood/condition becomes better.

Because いい changes form when it modifies a verb.

Here, よく is the adverbial form of いい:

• いい = good
• よく = well / in a good way

Then:

• よくなる = become good / become better

This is a very common pattern:

• 大きい → 大きくなる = become big / bigger
• 早い → 早くなる = become early / earlier
• いい → よくなる = become good / better

So 気分が少しよくなります literally means the mood becomes a little good, which is naturally translated as I feel a little better.

なります is the polite form of なる, which means to become.

So:

• よくなる = become better
• よくなります = becomes better / will become better

In this sentence, it shows a change of state:

• before: the mood is not as good
• after eating yogurt and apples: the mood improves a little

That is why なる is used instead of something like です.

少し means a little or slightly, and here it modifies よくなります.

So:

• 気分が少しよくなります = my mood gets a little better

It is describing the degree of improvement, not the amount of food.

Yes. Japanese often omits the subject when it is understood from context.

So this sentence could mean:

• When I eat yogurt and apples for breakfast, I feel a little better.
• When you eat yogurt and apples for breakfast, you feel a little better.
• When one eats yogurt and apples for breakfast, one feels a little better.

In real conversation, context usually makes it clear. Most likely, this sentence would be understood as I or you, depending on the situation.

It can mean either apple or apples.

Japanese nouns usually do not change form for singular and plural. Number is understood from context.

So:

• りんご = apple / apples
• ヨーグルト = yogurt

In English, depending on the meaning shown to the learner, you might translate this as an apple, apples, or just apple as a food item.

No. Common alternatives include:

• 朝ご飯（あさごはん）
• 朝ごはん
• 朝食（ちょうしょく）

Nuance:

• 朝ご飯 / 朝ごはん sounds everyday and casual
• 朝食 sounds a bit more formal or written

All are correct, but 朝ご飯に fits very naturally in ordinary speech.

It most naturally sounds like a usual or repeated result.

Because of 食べると, the sentence suggests something like:

• Whenever I eat yogurt and apples for breakfast, I feel a little better.

If you wanted to emphasize a one-time past experience, you would usually use a different form, such as:

• 食べたら、気分が少しよくなりました。

That would sound more like: After I ate them, I felt a little better.

So the original sentence suggests a general tendency or routine.