watasitati ha kyoukotuappaku wo rensyuusuru.

It is read:

Watashitachi wa kyōkotsu asshaku o renshū suru.

A breakdown:

• 私たち = watashitachi
• は = written ha, but pronounced wa here because it is the topic particle
• 胸骨圧迫 = kyōkotsu asshaku
• を = pronounced o
• 練習する = renshū suru

は marks the topic of the sentence.

So 私たち は means something like as for us or we as the topic.

In this sentence:

• 私たち = we
• は = marks we as the topic
• 胸骨圧迫を練習する = practice chest compressions

So the whole sentence is basically:

As for us, we practice chest compressions.

In natural English, you would usually just say We practice chest compressions.

This is one of the standard quirks of Japanese spelling.

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

So:

• はな would normally be read hana
• but 私は is read watashi wa

The same kind of thing happens with a couple of other particles in Japanese, such as を and へ in certain uses.

を marks the direct object of the verb.

Here, the direct object is 胸骨圧迫:

• 胸骨圧迫を = chest compressions
• 練習する = to practice

So 胸骨圧迫を練習する means to practice chest compressions.

A very common pattern in Japanese is:

noun + を + verb

For example:

• 日本語を勉強する = study Japanese
• ピアノを弾く = play the piano
• 胸骨圧迫を練習する = practice chest compressions

Japanese normally puts the main verb at the end of the sentence.

So while English says:

• We practice chest compressions

Japanese is structured more like:

• We / chest compressions / practice

That is completely normal in Japanese.

A rough word-for-word order here is:

• 私たち = we
• は = topic marker
• 胸骨圧迫 = chest compressions
• を = object marker
• 練習する = practice

胸骨圧迫 is a medical term meaning chest compressions.

It breaks down as:

• 胸骨 = sternum / breastbone
• 圧迫 = pressure / compression

So together, 胸骨圧迫 refers to the act of pressing on the chest, as in CPR.

In everyday conversation, people may also talk about CPR more broadly with terms like:

• 心肺蘇生 = cardiopulmonary resuscitation, CPR
• 胸骨圧迫 = chest compressions specifically

In Japanese, many actions are expressed as:

noun + する

Here:

• 練習 = practice
• する = do

So 練習する literally means to do practice, but in natural English it is simply to practice.

This is extremely common in Japanese. For example:

• 勉強する = to study
• 運動する = to exercise
• 掃除する = to clean
• 練習する = to practice

する is the plain form dictionary form.

します is the polite form.

So:

• 練習する = plain form
• 練習します = polite form

Both can mean practice, but the tone is different.

For example:

• 私たちは胸骨圧迫を練習する。 = plain style
• 私たちは胸骨圧迫を練習します。 = polite style

Textbooks often show plain forms when introducing grammar or dictionary entries.

Not always.

Japanese often leaves out subjects and topics when they are already clear from context.

So in many real situations, you could simply say:

胸骨圧迫を練習する。

That could still mean We practice chest compressions, depending on context.

However, 私たち is included here to make it explicit that the sentence is about we.

They mean the same thing: we or us.

• 私たち uses hiragana for たち
• 私達 uses the kanji 達

In modern Japanese, 私たち is very common and often feels a bit softer or more standard in general writing. Learners will frequently see both.

Usually yes, but Japanese pronouns are used differently from English pronouns.

In English, you usually need to say we. In Japanese, you often do not need to say 私たち if the meaning is already understood from context.

So 私たち does mean we, but Japanese uses it less often than English uses we.

Yes, it is grammatical and understandable.

It means to practice chest compressions.

Depending on context, native speakers might also use slightly different phrasing, such as:

• 胸骨圧迫の練習をする = do practice of chest compressions
• 胸骨圧迫を練習します = polite version

But the sentence you have is perfectly valid.

Correct. Normal Japanese writing usually does not use spaces between words.

So this sentence would normally be written as:

私たちは胸骨圧迫を練習する。

The spaced version is often used in beginner materials to make the sentence structure easier to see:

• 私たち
• は
• 胸骨圧迫
• を
• 練習する

That is a teaching aid, not standard Japanese formatting.

By itself, 練習する in plain non-past form often means a general action such as practice or will practice, depending on context.

So this sentence most naturally means:

• We practice chest compressions
• or We will practice chest compressions

If you specifically want We are practicing chest compressions, Japanese would more clearly say:

私たちは胸骨圧迫を練習している。

So the original sentence is not the best way to emphasize an ongoing action right now.

A useful gloss is:

• 私たち = we
• は = topic marker
• 胸骨圧迫 = chest compressions
• を = object marker
• 練習する = practice

So a literal gloss would be:

As for us, chest compressions practice/do.

That sounds unnatural in English, of course, but it helps show the Japanese structure.

The natural English translation is:

We practice chest compressions.