xǐyījī zhèngzài tuōshuǐ.

正在 marks an action that is in progress right now. It is similar to English be doing.

So in this sentence, 正在脱水 means the washing machine is currently spin-drying / in the spin cycle.

A very common pattern is:

Subject + 正在 + Verb

For example:

• 我正在吃饭。 = I am eating.
• 他正在看书。 = He is reading.

Yes. 在 and 正在 can both show an ongoing action.

• 洗衣机在脱水
• 洗衣机正在脱水

Both are natural.

The difference is that 正在 often sounds a little more explicit or slightly more formal/emphatic about right now.
In everyday speech, 在 is very common.

Because Chinese does not use 是 the way English uses is before most verbs.

In English, you say:

• The washing machine is spin-drying.

In Chinese, when you have an action verb like 脱水, you usually do not put 是 before it. Instead, Chinese uses markers like 在 / 正在 to show ongoing action.

So:

• 洗衣机正在脱水。 = correct
• 洗衣机是正在脱水。 = usually not correct in a normal sentence

Literally, 脱水 means remove water or dewater.

• 脱 = to remove / take off
• 水 = water

In the context of a washing machine, 脱水 means to spin out the water, so it is often translated as spin-dry or be on the spin cycle.

In other contexts, 脱水 can also mean dehydration or dehydrate, so the exact meaning depends on context.

The object is understood from context.

When you say 洗衣机正在脱水, listeners naturally understand that the washing machine is spin-drying the clothes/laundry inside. Chinese often leaves out an object if it is obvious.

If you want to say it more fully, you could say something like:

• 洗衣机正在给衣服脱水。

But in normal everyday speech, that would usually be unnecessary.

Yes, absolutely.

Chinese commonly lets machines, devices, or systems act as the subject of a sentence:

• 电脑正在更新。 = The computer is updating.
• 空调在运行。 = The air conditioner is running.
• 洗衣机正在脱水。 = The washing machine is spin-drying.

This is very natural and does not sound strange.

The structure is:

洗衣机 + 正在 + 脱水

That is:

subject + ongoing-action marker + verb

Breaking it down:

• 洗衣机 = washing machine
• 正在 = in the middle of / currently
• 脱水 = spin-dry / remove water

So the grammar is very straightforward.

Usually no.

正在 shows an action is ongoing, while 了 often marks a new situation or a completed/perfective event. They usually do not go together in a simple sentence like this.

So:

• 洗衣机正在脱水。 = The washing machine is spin-drying now.
• 洗衣机脱水了。 = The washing machine has started spin-drying / did the spin-drying / is now in the spin-dry state, depending on context.

If you want to emphasize that the action is happening right now, 正在 by itself is enough.

No. Another common expression is 甩干.

For example:

• 洗衣机正在脱水。
• 洗衣机正在甩干。

Both can refer to the spin-dry stage.
脱水 is very common on washing machines and in standard descriptions.
甩干 feels a bit more vivid, since it suggests spinning the water out.

Depending on region, brand labels, or context, you may see either one.

It is pronounced xǐ yī jī.

The middle syllable is 衣 meaning clothes, not 一 meaning one.

So:

• 洗 = xǐ
• 衣 = yī
• 机 = jī

This is important because some learners see yī and think of 一, but here it is a completely different character: 衣.

Yes, but it changes the feel.

• 洗衣机正在脱水。 = The washing machine is currently spin-drying.
• 洗衣机脱水。 = The washing machine spin-dries / the washing machine does spin-drying.

Without 正在, it can sound more general, like a statement about what the machine is doing or what function it has, rather than emphasizing the action happening right now.

If you are describing what is happening at this moment, 正在 is usually better.

In real-life context, it means the machine is removing water from the laundry inside.

Grammatically, 洗衣机正在脱水 does not spell out the object, but people naturally understand it as the washing machine carrying out the spin cycle on the clothes.

So the meaning is practical, not literal in the sense of the machine itself becoming dry.

Yes, but the focus changes.

• 洗衣机正在脱水。 = focus on the machine
• 衣服正在脱水。 = focus on the clothes

Both are possible, but 衣服正在脱水 can sound a little less common in everyday speech unless the context is very clear, because clothes do not usually dewater themselves. Native speakers more naturally say the machine is doing the action.

So 洗衣机正在脱水 is the more natural everyday sentence.