yuugata ni suupaa he ikeba, pan ya yooguruto ga tokubai ni natte irukoto ga arimasu.

行けば is the -ba conditional form of 行く.

• 行く = to go
• 行けば = if you go

So 夕方にスーパーへ行けば means if you go to the supermarket in the evening.

In a sentence like this, it can also feel close to when you go, especially when the speaker is talking about something that often happens under that condition.

Yes, に could also be used here.

With verbs of movement like 行く, both へ and に can mark the destination:

• スーパーへ行く
• スーパーに行く

The difference is small:

• へ emphasizes the direction toward a place
• に emphasizes the destination to a place

In everyday Japanese, both are very common, and in this sentence either one would sound natural.

Here, に marks the time: in the evening.

• 夕方 = evening
• 夕方に = in the evening

Time words in Japanese sometimes take に, and sometimes they do not. With a word like 夕方, both 夕方スーパーへ行けば and 夕方にスーパーへ行けば are possible, though に makes the time relationship a little clearer.

や is used to give examples from a larger group.

So:

• パンやヨーグルト = bread, yogurt, and things like that

This is different from と, which gives a more complete list.

Compare:

• パンとヨーグルト = bread and yogurt
• パンやヨーグルト = bread and yogurt, among other things

Here, や suggests these are just some items that may be on sale, not the only ones.

Here, が marks パンやヨーグルト as the subject of the clause:

• パンやヨーグルトが特売になっている
• bread and yogurt are on special sale

Using が is natural because the sentence is presenting what happens or what may be found in that situation.

If you used は, it would sound more contrastive or topical, as if you were specifically talking about bread and yogurt in contrast to other items.

特売 means special sale, special bargain, or discount sale.

In stores, it refers to items being sold at a reduced price for a promotion.

So:

• 特売になる = to go on special sale / to become a sale item

This is a very common word in shopping contexts.

The pattern here is:

• A に なる = to become A

So:

• 特売になる = to become a special-sale item / to go on sale

The に marks the result of the change. This is the same grammar as:

• 元気になる = to become well
• 先生になる = to become a teacher
• 静かになる = to become quiet

Here, 特売 behaves like the result state.

なっている shows the resulting state after a change has happened.

• 特売になる = to go on sale
• 特売になっている = to be in the state of being on sale

So the sentence is not just saying the items become discounted, but that when you go, they are already on sale.

This is a very common use of 〜ている with change-of-state verbs:

• 結婚している = is married
• 開いている = is open
• 壊れている = is broken

Likewise:

• 特売になっている = is on special sale

In this sentence, 〜ことがあります means there are times when..., or more naturally, sometimes....

So:

• パンやヨーグルトが特売になっていることがあります
• There are times when bread and yogurt are on sale
• Bread and yogurt are sometimes on sale

This pattern is often used to describe something that happens occasionally, not always.

Because こと is functioning like a noun meaning the fact / the event / the situation.

The structure is basically:

• [clause]こと = the fact that [clause]
• [clause]ことがある = there are times when [clause]

So in this sentence:

• パンやヨーグルトが特売になっていること = the situation/event of bread and yogurt being on sale
• ...ことがあります = there are such occasions

That is why the whole こと phrase is followed by が.

Grammatically, 行けば is if you go.

But in natural English, depending on context, it may sound better as:

• If you go to the supermarket in the evening, ...
• When you go to the supermarket in the evening, ...

Why? Because the speaker is describing something that can happen under a certain condition, and English often uses when for repeated real-life situations.

So the Japanese grammar is conditional, but the best English translation may vary.

It is talking about an occasional possibility.

The key part is ことがあります, which means:

• it happens sometimes
• there are cases when it happens
• it is not guaranteed

So the sentence does not mean that bread and yogurt are always on sale in the evening. It means that if you go then, you may sometimes find them discounted.

This is very normal in Japanese.

Inside longer sentences, subordinate clauses often use plain forms, while the main sentence ends politely.

Here:

• 行けば = plain conditional form
• なっている = plain form inside the clause
• あります = polite form at the end

Japanese politeness is usually shown at the end of the sentence, so this mixture is completely natural.

Yes. A simpler version might be:

• 夕方にスーパーへ行くと、パンやヨーグルトが特売になっていることがあります。
• 夕方にスーパーへ行くと、パンやヨーグルトが安くなっていることがあります。

Or even more directly:

• 夕方にスーパーへ行くと、パンやヨーグルトが特売のことがあります。

But the original sentence is natural and clear. It sounds a little careful and descriptive, which is often useful in textbook-style Japanese.

It breaks down like this:

• 夕方に = in the evening
• スーパーへ = to the supermarket
• 行けば = if you go
• パンやヨーグルトが = bread, yogurt, and similar items
• 特売になっている = are on special sale
• ことがある = there are times when / sometimes

So the full structure is:

• If you go to the supermarket in the evening, there are times when bread, yogurt, and the like are on special sale.

That is why a natural English translation is often:

• If you go to the supermarket in the evening, bread and yogurt are sometimes on sale.