dendouasisutozitensya ha takai.

It is commonly read でんどうアシストじてんしゃ.

Breakdown:

• 電動 = でんどう = electric-powered
• アシスト = assist
• 自転車 = じてんしゃ = bicycle

So the whole noun means an electric-assist bicycle or electric bicycle.

When は is used as a particle, it is pronounced wa, not ha.

So in this sentence:

• written: 電動アシスト自転車 は 高い。
• pronounced: でんどうアシストじてんしゃ は たかい。

This is one of the first pronunciation exceptions learners meet in Japanese.

は marks the topic of the sentence.

So 電動アシスト自転車は高い means something like:

• As for electric-assist bicycles, they are expensive
• or more naturally, Electric-assist bicycles are expensive

It tells the listener what the sentence is about, and then 高い gives information about that topic.

Using は makes this sound like a general statement about the topic.

• 電動アシスト自転車は高い。
  = Electric-assist bicycles are expensive / As for electric-assist bicycles, they’re expensive

If you used が instead, it could sound more like you are identifying or emphasizing the subject in a particular context:

• 電動アシスト自転車が高い。

That might be used in a situation like:

• Which kind is expensive?
• The electric-assist bicycles are.

So は is the more natural choice for a broad statement.

高い is an い-adjective.

It can mean:

• high
• tall
• expensive

In this sentence, because the topic is a bicycle, 高い means expensive, not tall or high.

Also, in Japanese, an い-adjective can end a sentence by itself. You do not need a separate word for is in plain style.

So:

• 高い。 = is expensive / are expensive

Japanese often does not use a separate word corresponding directly to English is when the predicate is an adjective.

In English:

• The bicycle is expensive

In Japanese:

• 自転車は高い。

The adjective 高い already functions as the predicate, so no extra is is needed.

If you want to make it polite, you can add です:

• 電動アシスト自転車は高いです。

Japanese nouns usually do not show singular vs. plural the way English does.

So 電動アシスト自転車 could refer to:

• an electric-assist bicycle
• electric-assist bicycles in general

In this sentence, the most natural interpretation is a general statement:

• Electric-assist bicycles are expensive

But depending on context, it could also mean:

• That electric-assist bicycle is expensive

Context tells you which meaning is intended.

Japanese does not normally use articles like a or the, and it usually does not mark plurals the way English does.

So 電動アシスト自転車 can mean:

• an electric-assist bicycle
• the electric-assist bicycle
• electric-assist bicycles

You figure out the exact meaning from context.

That is very normal in Japanese and can feel strange at first for English speakers.

Yes. Japanese often combines several elements into one long noun phrase.

Here:

• 電動 = electric-powered
• アシスト = assist
• 自転車 = bicycle

Together they form one unit: electric-assist bicycle.

Japanese does this a lot, so long compound nouns are very common.

Yes. 高い has a broad meaning related to being high.

Depending on context, it can mean:

• high
• tall
• expensive

Examples:

• 山が高い = The mountain is high
• 背が高い = Someone is tall
• 値段が高い = The price is high / expensive

In 電動アシスト自転車は高い, the natural meaning is expensive.

No. Normal Japanese writing usually does not use spaces between words.

So this sentence would normally be written as:

• 電動アシスト自転車は高い。

Spaces are often added in beginner materials to make the structure easier to see:

• 電動アシスト自転車 | は | 高い

But in real Japanese text, you usually will not see those spaces.

The polite version is:

• 電動アシスト自転車は高いです。

The difference is mainly politeness:

• 高い。 = plain
• 高いです。 = polite

Both mean the same thing, but 高いです is more appropriate in everyday polite conversation, with strangers, teachers, coworkers, and so on.