tikyuu ha wakusei desu.

It is read:

ちきゅう は わくせい です
chikyū wa wakusei desu

Word by word:

• 地球 = ちきゅう = chikyū
• は = written ha, but pronounced wa here
• 惑星 = わくせい = wakusei
• です = desu

A natural English-style pronunciation guide would be roughly:

• chikyū ≈ chee-kyoo
• wakusei ≈ wah-koo-say
• desu ≈ dess

Also, in normal speech, です often sounds closer to des than a fully pronounced de-su.

Because は has a special pronunciation when it is used as the topic particle.

So:

• as a normal syllable, は = ha
• as the particle marking the topic, は = wa

This is one of the first spelling/pronunciation exceptions learners meet in Japanese. In this sentence, は is not part of a word; it is a grammar marker, so it is pronounced wa.

は marks the topic of the sentence.

In 地球は惑星です, the topic is 地球 (the Earth). A very literal way to think of it is:

• As for the Earth, it is a planet.

That sounds a little unnatural in English, but it helps show what は does. It sets up what the sentence is about.

A very common beginner pattern is:

X は Y です
= X is Y

So here:

• 地球 = Earth
• は = topic marker
• 惑星 = planet
• です = polite copula

This is a very common question.

In simple terms:

• は marks the topic
• が marks the subject more directly

For a general statement like Earth is a planet, は is the natural choice because the sentence is presenting information about Earth.

So:

• 地球は惑星です = As for Earth, it is a planet / Earth is a planet

If you used が instead, the nuance would change. 地球が惑星です could sound like you are specifically identifying Earth as the thing that is a planet, often in a context where that contrast matters. It is not the usual neutral textbook way to state a general fact.

So for this sentence, は is the standard and expected choice.

です is the polite copula. In beginner textbooks, it is often translated as is, but it is not exactly the same as the English verb to be in every situation.

In this sentence, です links 地球 and 惑星 in a polite way:

• 地球は惑星です = Earth is a planet

You can think of です here as the polite ending that makes the sentence complete and courteous.

A plain, less polite version would be:

地球は惑星だ。

So:

• です = polite
• だ = plain/casual

Japanese sentence structure is often different from English.

English:

• Earth is a planet.

Japanese:

• Earth + topic marker + planet + is

So the pattern is:

X は Y です

Japanese usually puts the main predicate at the end of the sentence. That is why です comes last.

A helpful literal breakdown is:

• 地球 = Earth
• は = as for
• 惑星 = planet
• です = is

Literal gloss:

• As for Earth, planet is

Natural English:

• Earth is a planet.

Japanese does not have articles like English a, an, and the.

So 惑星 by itself can mean:

• a planet
• the planet
• sometimes just planet/planets

The exact meaning depends on context.

In this sentence, the natural English translation is Earth is a planet, so 惑星 is understood as a planet.

This is normal in Japanese. Learners often want every English word to match one Japanese word, but articles usually do not have direct equivalents.

No. Japanese is normally written without spaces.

So the standard written form is:

地球は惑星です。

The spaces in 地球 は 惑星 です are usually added only for learners to make the parts easier to see.

Also, Japanese normally uses the full stop 。 at the end, rather than an English period.

Yes. A casual/plain version is:

地球は惑星だ。

This means the same thing, but it is less polite than です.

Very roughly:

• 地球は惑星です。 = polite
• 地球は惑星だ。 = plain/casual

In writing, you might also see very casual or headline-style omissions, but for a normal complete sentence, beginners should use either:

• 地球は惑星です。
• 地球は惑星だ。

Here is a useful breakdown:

地球 (ちきゅう) = Earth

• 地 = earth, ground
• 球 = sphere, ball, globe

So 地球 literally gives the idea of the earth/globe.

惑星 (わくせい) = planet

• 星 = star
• 惑 is part of the word 惑星, though by itself it is not something beginners usually use often in isolation

You do not need to translate each kanji separately every time, but knowing the parts can help you remember the vocabulary.

Because Japanese does not use articles like English, the sentence is a little more flexible in theory than the English translation.

But in normal context, 地球は惑星です is naturally understood as:

Earth is a planet.

It would not normally be taken to mean something strange like Earth is the planet unless the surrounding context strongly forced that reading.

So for practical purposes, this sentence is a straightforward factual statement:

• The Earth is a planet
• or Earth is a planet

Both are good English translations depending on style.