tabako ha takai.

は marks the topic of the sentence.

So タバコは高い is literally closer to:

• As for tobacco/cigarettes, [they are] expensive
• Speaking of cigarettes, [they are] expensive

It does not directly mean is. Instead, it tells you what the sentence is talking about.

Both は and が can mark something before an adjective, but they give different nuance.

• は = topic; often used for general statements, contrast, or things already under discussion
• が = subject; often used when identifying something, answering a question, or emphasizing what has the property

So:

• タバコは高い。 = Cigarettes are expensive / As for cigarettes, they’re expensive
• タバコが高い。 = It’s cigarettes that are expensive or The cigarettes are expensive, depending on context

In a simple textbook sentence making a general statement, は is very natural.

Japanese often does not need a separate word for is in this kind of sentence.

高い is an い-adjective, and in Japanese an い-adjective can act like the predicate by itself.

So:

• タバコは高い。 = Cigarettes are expensive.

There is no missing word. The sentence is already complete.

It can, but it does not have to.

• タバコは高い。 = plain style
• タバコは高いです。 = polite style

Both are correct.

Even though 高い already finishes the sentence, adding です makes it more polite. This is very common in everyday Japanese.

高い can mean:

• high
• tall
• expensive

In タバコは高い, the natural meaning is expensive, because tobacco/cigarettes are something you buy.

Japanese adjectives often have several related meanings, and context tells you which one is intended.

It can refer to tobacco, cigarettes, or smoking in general, depending on context.

In everyday speech, タバコ very often means cigarettes.

So タバコは高い will usually be understood as Cigarettes are expensive.

Also, タバコ is written in katakana because it is a loanword, historically from Portuguese.

Japanese nouns usually do not change form for singular vs. plural.

So タバコ can mean:

• a cigarette
• cigarettes
• tobacco

The context tells you which one is meant.

In this sentence, the meaning is usually cigarettes in general, so English often uses the plural.

Japanese does not use articles like a or the, and nouns usually do not show plural with a special ending.

So タバコ does not tell you by itself:

• a cigarette
• the cigarette
• cigarettes

You understand that from context.

That is why one short Japanese sentence can correspond to several possible English translations.

The pattern is:

noun + は + い-adjective

So:

• タバコ = noun
• は = topic particle
• 高い = い-adjective

This is a very common pattern for saying that something has a certain quality:

• この本は面白い。 = This book is interesting.
• 日本は遠い。 = Japan is far.
• 水は冷たい。 = Water is cold.

Japanese basic word order is often described as topic/comment or subject/object/verb, and the main descriptive element often comes near the end.

In タバコは高い, the sentence first introduces the topic, タバコ, and then says something about it, 高い.

So the structure is very natural for Japanese:

• As for cigarettes, expensive

In natural English, we rearrange that to Cigarettes are expensive.

Add です:

• タバコは高いです。

That is the standard polite version.

You could also say:

• タバコは高いですね。

The ね adds a feeling like isn’t it? or you know, often inviting agreement.

Because 高い is an い-adjective, it changes like this:

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

So:

• タバコは高くない。 = Cigarettes are not expensive.
• タバコは高かった。 = Cigarettes were expensive.
• タバコは高くなかった。 = Cigarettes were not expensive.

Polite forms:

• タバコは高くないです。
• タバコは高かったです。
• タバコは高くなかったです。

Although the topic particle is written は, when used as a particle it is pronounced wa.

So:

• タバコは高い is pronounced roughly:
• tabako wa takai

This is a very important beginner point, because the writing and pronunciation do not match in this one case.