syoumikigen ga mizikai gyuunyuu ha, nehuda no yoko ni tokubai to kaite arimasita.

A helpful breakdown is:

• 賞味期限が短い牛乳は = as for the milk whose best-by date was near / short
• 値札の横に = next to the price tag
• 特売と = that it was a special sale / on sale
• 書いてありました = was written

So the sentence is built like this:

• [relative clause + noun] は
• [location] に
• [content] と
• 書いてありました

A very literal gloss would be:

As for the milk whose best-by date was short, next to the price tag, “special sale” was written.

Natural English would be something like:

The milk with the soonest best-by date had “special sale” written next to the price tag.

Because Japanese uses a relative clause directly before the noun it modifies.

So:

• 賞味期限が短い = whose best-by date is short / near
• 牛乳 = milk

Together:

• 賞味期限が短い牛乳 = milk whose best-by date is near

Unlike English, Japanese does not need words like that, which, or whose here.

Compare:

• English: the milk whose best-by date is near
• Japanese: 賞味期限が短い牛乳

This is a very common Japanese pattern:

• 背が高い人 = a person who is tall
• 日本で作られた車 = a car made in Japan
• 昨日買った本 = the book I bought yesterday

Inside a relative clause, が is usually the most natural marker for the subject.

Here, 賞味期限 is the subject of 短い:

• 賞味期限が短い = the best-by date is short/near

If you used は there, it would sound more like a separate topic statement, which is less natural inside this modifier.

So:

• 賞味期限が短い牛乳 = natural
• 賞味期限は短い牛乳 = unnatural in this context

A simple way to think about it:

• が marks the subject inside the descriptive clause
• は marks the main topic of the whole sentence

And in this sentence, the main topic is:

• 賞味期限が短い牛乳は = as for the milk with the near best-by date

Yes, 賞味期限の短い牛乳 is also natural.

Both can mean roughly:

• milk with a short/near best-by date

The difference is subtle:

• 賞味期限が短い牛乳 feels like a full clause: milk whose best-by date is short
• 賞味期限の短い牛乳 feels a bit more like a compact descriptive phrase: milk with a short best-by date

In many everyday situations, the difference is small.
For learners, が is a very safe and standard choice in relative clauses.

Yes, a literal English translation sounds strange.

• 賞味期限 = best-by date / shelf-life date
• 短い literally means short

But in context, 賞味期限が短い means the remaining time until that date is short, or that the date is close.

So natural English would be:

• milk with a soon best-by date
• milk nearing its best-by date
• milk with a close expiration date
  (though 賞味期限 is not exactly the same as expiration date)

This is a good example of how Japanese often says something literally like the period is short, while English prefers the date is near.

This is a very common vocabulary question.

• 賞味期限 = best-by date

  • the food is expected to be at its best quality before this date
  • it may still be okay after that date

• 消費期限 = use-by / expiration date

  • food should be consumed by that date
  • it is stricter, often used for foods that spoil quickly

So in this sentence, 賞味期限 suggests a best-by type of date rather than a hard safety deadline.

Because the entire noun phrase becomes the topic of the sentence.

• 賞味期限が短い牛乳 = the milk with the near best-by date
• は = as for...

So:

• 賞味期限が短い牛乳は、... = As for the milk with the near best-by date, ...

This does not mean 牛乳 alone is marked by は.
Rather, the whole phrase before は is the topic.

Japanese often works like this:

• 昨日買った本は面白かった。 = The book I bought yesterday was interesting.

Here too, the whole phrase 昨日買った本 is the topic.

• 値札 = price tag
• の = of
• 横 = side / beside
• に = location marker

So:

• 値札の横に = beside the price tag / next to the price tag

This is a common pattern:

• 机の横に = next to the desk
• 店の前に = in front of the store
• 箱の中に = inside the box

Here, に marks the place where the writing was.

Because に marks the place where something exists or is located.

Since the sentence ends with 書いてありました, which describes a written state existing somewhere, に is the natural particle for the location.

So:

• 値札の横に書いてありました = it was written next to the price tag

You can think of it as:

• At the place next to the price tag, the writing existed.

特売 means:

• special sale
• special bargain
• sale item
• on sale

In a store, it often means something is being sold at a discounted price for promotional reasons.

So 特売と書いてありました means that there was a sign or label saying it was on sale or a special.

Because と marks the content of writing, speech, or thought.

Here, 特売 is the exact content that was written:

• 特売と書いてありました
• “special sale” was written

This pattern is very common:

• 「休み」と書いてある = it says “closed” / “holiday”
• 名前を書く = write a name
• 「出口」とあります = it says “exit”

So と here is like marking the quoted content, even if English would not always use quotation marks.

Because 書いてある does not focus on the act of writing itself.
It focuses on the resulting state: something has been written and is there.

Compare:

• 書きました = someone wrote it
• 書いてあります = it is written / has been written and remains there

In this sentence, the important thing is not who wrote it, but the fact that the sign/label said 特売.

So:

• 特売と書いてありました = it had “special sale” written = it said “special sale”

This is extremely common for signs, labels, notices, and instructions.

This is a very important grammar point.

書いています

Usually describes:

• an ongoing action: is writing
• or a general state, depending on the verb

書いてあります

Specifically describes:

• something that has been written intentionally
• and now exists in that written state

So:

• 壁に名前が書いています → unnatural
• 壁に名前が書いてあります → a name is written on the wall

Another example:

• ドアに「押す」と書いてあります。 = “Push” is written on the door.

The nuance of ～てある is:

• someone did it intentionally
• and now the result remains

書かれていました is also grammatically possible, but it has a different feel.

• 書いてありました focuses on the resulting written state
• 書かれていました is a passive form: was written

In store-sign contexts, 書いてありました sounds very natural because it emphasizes what was displayed there.

Compare:

• 特売と書いてありました = it said “special sale” / “special sale” was written there
• 特売と書かれていました = “special sale” was written
  slightly more passive and less everyday in tone here

So 書いてありました is a very natural choice for signs and labels.

Because the speaker is reporting what they saw at that time.

• 書いてあります = it is written
• 書いてありました = it was written

The past tense can suggest:

• the speaker is recalling what they saw earlier
• the situation belonged to a past moment

For example:

• 店で見たとき、特売と書いてありました。 = When I saw it at the store, it said “special sale.”

Yes. Japanese often leaves things unstated when they are obvious from context.

Here, what was written is something like:

• on a sign
• on a label
• on a notice
• on the tag area next to the price tag

Japanese does not need to say that explicitly if the context makes it clear.

So English may need to add something:

• There was a sign next to the price tag saying “special sale.”
• “Special sale” was written next to the price tag.

Both capture the idea.

Not necessarily.

In Japanese, 書いてある is used very broadly for written text, including:

• printed signs
• labels
• notices
• stickers
• handwritten notes

So it does not have to mean someone physically handwrote 特売 right then. It just means that those words were displayed in writing.

The comma shows a pause after the topic:

• 賞味期限が短い牛乳は、値札の横に特売と書いてありました。

It helps the reader process the sentence:

1. topic: the milk with the near best-by date
2. comment: had “special sale” written next to the price tag

The comma is not mandatory in all cases, but it is very common after a long topic phrase like this.

Not really. Because of 値札の横に, the natural reading is that the writing was next to the price tag, not directly on the milk carton.

So the sentence suggests something like:

• a shelf label
• a sign
• a note near the product display

That is why a natural English version is often:

• Next to the price tag, it said “special sale” for the milk nearing its best-by date.

A very literal translation:

• As for the milk whose best-by date was short, “special sale” was written next to the price tag.

A more natural English translation:

• The milk nearing its best-by date had “special sale” written next to the price tag.
• The milk with the soonest best-by date was marked “special sale” next to the price tag.
• Next to the price tag, the milk nearing its best-by date was labeled “special sale.”

The literal version helps you see the grammar, while the natural version sounds better in English.