sentakumono wo tatanda ato, kansouki no naka wo kirei ni simasu.

Because あと meaning after is usually attached to the past short form of a verb when it means after doing X.

So:

• たたむ = to fold
• たたんだ = folded
• たたんだあと = after folding

This pattern is very common:

• ご飯を食べたあと = after eating a meal
• 宿題をしたあと = after doing homework

So in your sentence, 洗濯物をたたんだあと means after folding the laundry.

Here, あと means after in a time-sequence sense.

It shows that one action happens first, and then another action happens afterward:

1. 洗濯物をたたむ = fold the laundry
2. 乾燥機の中をきれいにする = clean the inside of the dryer

So あと connects those two actions and tells you the order.

A useful comparison:

• 〜まえ = before
• 〜あと = after

For example:

• 寝るまえ = before sleeping
• 寝たあと = after sleeping

洗濯物 means laundry or washed clothes.

It often refers to clothes or fabric items as laundry in a practical, everyday sense. Depending on context, it can mean:

• clothes being washed
• washed clothes
• laundry to fold
• laundry hanging to dry

In this sentence, it most naturally means the laundry/clothes that are being folded.

That を marks 洗濯物 as the direct object of たたんだ.

So:

• 洗濯物をたたむ = to fold the laundry

The thing being folded is 洗濯物, so it takes を.

This is the normal object marker used with action verbs:

• 本を読む = read a book
• ドアを開ける = open the door
• 洗濯物をたたむ = fold the laundry

Yes, 中 means inside, so it feels like a location. But in this sentence, 乾燥機の中 is being treated as the thing affected by きれいにします.

So:

• 乾燥機の中をきれいにします = make the inside of the dryer clean / clean the inside of the dryer

Here, を marks the area/object being cleaned.

This is natural in Japanese. Sometimes a place-like expression takes を when it is the thing being affected by the action.

Compare:

• 部屋をきれいにする = clean the room / make the room clean
• 机の上をきれいにする = clean the top of the desk
• 乾燥機の中をきれいにする = clean the inside of the dryer

So even though 中 is location-related, the whole phrase 乾燥機の中 functions like the object of きれいにする.

Literally, it means the inside of the dryer.

Breaking it down:

• 乾燥機 = dryer / drying machine
• の = of
• 中 = inside

So:

• 乾燥機の中 = the inside of the dryer

The particle の links nouns together, and here it works like English of or the apostrophe-s idea.

Other similar examples:

• 箱の中 = inside the box
• 部屋の中 = inside the room
• かばんの中 = inside the bag

きれい is a na-adjective.

Its basic meaning is clean or beautiful, depending on context. In this sentence, it means clean.

Because it comes before にします, it changes into an adverb-like form:

• きれい → きれいに

So:

• きれいにする = to make clean / to clean

This is a very common pattern:

• 静かにする = make it quiet
• 元気にする = cheer someone up / make someone well
• きれいにする = clean / make clean

Literally, it means make clean.

The pattern is:

• A を B にする = make A into B / make A become B

So here:

• 乾燥機の中をきれいにします
• literally: I make the inside of the dryer clean

In natural English, that usually becomes:

• I clean the inside of the dryer

So both ideas are correct:

• literal grammar meaning: make clean
• natural English meaning: clean

Both can work, but they are a little different in nuance.

• きれいにします = make it clean / clean it up
• 掃除します = do cleaning / clean

きれいにします focuses on the result: it becomes clean.
掃除します focuses more on the action of cleaning itself.

So:

• 乾燥機の中をきれいにします sounds like I clean the inside of the dryer so that it is clean
• 乾燥機の中を掃除します would also be understandable and natural in many situations

Japanese often uses きれいにする for everyday cleaning tasks.

Because Japanese often leaves out the subject when it is understood from context.

So even though English usually needs something like:

• I clean the inside of the dryer
• we clean the inside of the dryer

Japanese often just says:

• 乾燥機の中をきれいにします

The subject is omitted because it is obvious from the situation.

This is extremely common in Japanese. A full sentence with a stated subject is possible, but often unnecessary:

• 私は乾燥機の中をきれいにします = I clean the inside of the dryer

Usually, though, 私は would be dropped unless needed for emphasis or contrast.

Yes, たたむ is the normal verb for fold.

It is used for clothes, laundry, paper, umbrellas, and other things that can be folded:

• 服をたたむ = fold clothes
• 洗濯物をたたむ = fold the laundry
• 紙をたたむ = fold paper

So 洗濯物をたたんだあと is a very natural way to say after folding the laundry.

It can be either, depending on context.

Japanese nouns usually do not clearly show singular vs. plural unless something in the sentence makes it clear.

So 洗濯物 could mean:

• a piece of laundry
• laundry in general
• clothes/items of laundry

In this sentence, English would normally translate it as the laundry, not a laundry item, because that fits the situation best.

No, standard Japanese normally does not use spaces between words like this.

The sentence would usually be written as:

洗濯物をたたんだあと、乾燥機の中をきれいにします。

Spaces are often added in teaching materials to help learners see the parts more clearly.

So the spaced version is for readability, not normal everyday writing.

It can be used with both.

With verbs:

• 食べたあと = after eating
• たたんだあと = after folding

With nouns, you usually use の:

• 授業のあと = after class
• 仕事のあと = after work

So the pattern is:

• verb (past short form) + あと
• noun + の + あと

That is why this sentence uses たたんだあと, not たたむのあと.

Yes.

Because します is non-past polite form, it can mean:

• a present/future action
• a habitual action
• something someone regularly does

So depending on context, this sentence could mean:

• After folding the laundry, I clean the inside of the dryer.
• After folding the laundry, we clean the inside of the dryer.
• After I fold the laundry, I will clean the inside of the dryer.

Japanese often leaves that kind of time interpretation to context.