bangohan no ato, tyawan wo araimasu.

A natural breakdown is:

• 晩ご飯 = dinner
• の = links dinner to after
• あと = after
• 茶碗 = bowl / rice bowl, and sometimes by extension the dishes being washed
• を = marks the direct object
• 洗います = wash / will wash

So the structure is basically:

• [after dinner], [bowls/dishes] [wash]

Japanese often puts time expressions first and the verb at the end.

Here, の connects two nouns:

• 晩ご飯 = dinner
• あと = after

So 晩ご飯のあと literally means something like:

• the after of dinner
• more naturally, after dinner

This is a very common pattern in Japanese:

• 食事のあと = after the meal
• 授業のあと = after class
• 仕事のあと = after work

So の is not showing possession here in the English 's sense. It is more broadly a linker between nouns.

あと means after in this sentence.

In Japanese, あと can be a noun, which is why it works nicely with の:

• 晩ご飯のあと = after dinner

You may also see it written as:

• 後

But in beginner materials, it is often written in hiragana as あと.

It can also appear in other patterns, such as:

• 食べたあと = after eating
• 帰ったあと = after going home

So あと is a very common word for expressing what happens later.

The comma after あと helps separate the time phrase from the main action:

• 晩ご飯のあと、 = after dinner,
• 茶碗を洗います。 = I wash the bowls.

It makes the sentence easier to read, especially when a sentence begins with a time or setting phrase.

It is not always required, but it is very natural to include it here.

Even though the kanji are:

• 茶 = tea
• 碗 = bowl

the word 茶碗 usually means a rice bowl or bowl used for food, not specifically a bowl for tea in everyday modern usage.

In a sentence like 茶碗を洗います, it can mean:

• I wash the bowls
• or more generally, I wash the dishes, depending on context

Japanese often uses one concrete item to represent part of a larger activity. So this may not mean that only bowls are being washed and nothing else.

を marks the direct object of the verb—the thing being acted on.

Here:

• 茶碗を洗います
• wash the bowls

So 茶碗 is the thing that gets washed.

This is one of the most basic uses of を:

• パンを食べます = eat bread
• 本を読みます = read a book
• 服を買います = buy clothes

Japanese sentences very often place the main verb at the end.

So instead of English order like:

• I wash the bowls after dinner

Japanese prefers:

• After dinner, bowls wash
• more naturally, After dinner, I wash the bowls

That is why 洗います comes last.

A very common beginner rule is:

• time expression + object + verb

For this sentence:

• 晩ご飯のあと = time phrase
• 茶碗を = object
• 洗います = verb

洗います is the polite non-past form of the verb 洗う.

• 洗う = plain/dictionary form
• 洗います = polite form

Japanese often uses the polite -ます form in neutral conversation, in textbooks, and when speaking respectfully.

Also, the non-past form in Japanese can mean:

• a habitual action: I wash
• a future action: I will wash

So this sentence could mean:

• I wash the bowls after dinner
  or
• I will wash the bowls after dinner

depending on context.

The subject is omitted because Japanese often leaves out information that is obvious from context.

So 晩ご飯のあと、茶碗を洗います。 does not explicitly say:

• I wash the bowls after dinner
• we wash the bowls after dinner
• someone washes the bowls after dinner

In many learning contexts, it is understood as I wash the bowls after dinner.

Japanese does this all the time. If the listener already knows who the topic is, there is usually no need to say it.

Yes. Some common alternatives are:

• 晩ご飯のあとで、茶碗を洗います。
• 夕食のあと、茶碗を洗います。
• 晩ご飯を食べたあと、茶碗を洗います。

These are all natural, but they differ slightly:

• 晩ご飯のあと = after dinner
• 夕食のあと = after dinner, a bit more formal because 夕食 is more formal than 晩ご飯
• 晩ご飯を食べたあと = after eating dinner, more explicit

So the original sentence is simple and very natural.

No. In normal Japanese, this would usually be written without spaces:

• 晩ご飯のあと、茶碗を洗います。

Spaces are often added in beginner materials to make the parts easier to read.

So the spaced version is for learning, but the standard written form does not use those spaces.