atai ga takai.

Here, 値 is read ね. So the sentence is ね が たかい.

The kanji 値 can also be read あたい in other contexts, especially when it means a numerical value, as in math or programming. But in a short sentence like this, meaning price/value, ね is the natural reading.

値 means something like price, value, or worth, depending on context.

That means this sentence can describe:

• a high price
• a high market value
• high worth

Japanese often leaves the exact nuance to the situation. If you are talking about buying something, it may feel like the price is high. If you are talking about worth or merit, it may feel more like the value is high.

が marks 値 as the thing that has the property 高い.

So the structure is basically:

値 = the price/value
が = subject marker
高い = is high

This is a very normal pattern in Japanese: noun + が + adjective.

If you changed it to は, you would be making 値 the topic instead. That can sound more contrastive or like you are specifically commenting on the price/value as opposed to something else.

Yes, you could. But it has a slightly different feel.

• 値が高い = a neutral statement: the price/value is high
• 値は高い = as for the price/value, it is high

Using は can imply contrast or focus. For example, it may suggest something like The price is high, but... or At least the value is high depending on context.

The sentence does not say whose price/value is high. That part is understood from context.

For example, if you were already talking about a house, a car, or a stock, 値が高い could mean:

• Its price is high
• Its value is high

This kind of omission is very common in Japanese. English usually needs a subject like it or a phrase like this item, but Japanese often leaves that unstated when it is obvious.

高い is an い-adjective.

In this sentence, it is in its plain, non-past form. That can mean either:

• a present statement
• a general statement

Some useful forms are:

• 高い = is high
• 高くない = is not high
• 高かった = was high
• 高くなかった = was not high

Because it is an い-adjective, it can end the sentence by itself. You do not need だ after it.

Often, yes.

The basic meaning of 高い is high, but when it is used with price-related words, English often translates it as expensive.

For example:

• 値が高い = the price/value is high
• 値段が高い = the price is high / it is expensive

So in context, 高い may be understood as expensive, even though the literal idea is high.

値が高い is natural, but it is a little more context-dependent than 値段が高い.

Very roughly:

• 値段が高い = the most everyday way to say the price is high
• 価格が高い = more formal, business-like
• 値が高い = shorter, a bit more abstract, and can mean price or value depending on context

So if you simply want to say This is expensive in everyday conversation, 値段が高い is often clearer. 値が高い can sound slightly more compact or literary.

This sentence is in the plain style.

Japanese plain-style sentences often end with the adjective itself:

• 値が高い。

If you want to make it polite, you can say:

• 値が高いです。

Both are grammatical. The version without です is casual/plain, while the version with です is polite.

Since 高い is an い-adjective, you change the adjective itself.

Common forms:

• 値が高くない。 = The price/value is not high.
• 値が高かった。 = The price/value was high.
• 値が高くなかった。 = The price/value was not high.

Polite versions would be:

• 値が高いです。
• 値が高くないです。 or 値が高くありません。
• 値が高かったです。
• 値が高くなかったです。 or 値が高くありませんでした。

No. Normal Japanese is usually written without spaces:

値が高い。

Spaces are often added in teaching materials to help beginners see the parts of the sentence more clearly. In real Japanese text, you normally would not see them.