kyou no zyugyou no pointo ha howaitoboodo ni kaite arimasu.

Each の links nouns together.

• 今日の授業 = today’s class / today’s lesson
• 授業のポイント = the points of the lesson or the key points in the lesson

So the whole chunk 今日の授業のポイント means something like the key points of today’s lesson.

A useful way to see it is:

• 今日 → modifies 授業
• 今日の授業 → then modifies ポイント

So the structure is layered, not random.

Yes, ポイント comes from English point, but in Japanese it often means:

• main point
• key point
• important takeaway
• highlight

So in this sentence, 授業のポイント is not just a single dot-point or grammatical point. It means the important points / key takeaways of the lesson.

は marks the topic of the sentence.

Here, the topic is:

• 今日の授業のポイントは = As for the key points of today’s lesson...

Then the rest of the sentence says what is true about that topic:

• ホワイトボードに書いてあります = they are written on the whiteboard

So は sets up what we are talking about, not necessarily the grammatical subject in the same way as English.

Here, に marks the location where something exists in a resulting state.

With 書いてあります, the sentence focuses on the result: something has been written and is now there. So:

• ホワイトボードに書いてあります = is written on the whiteboard

This is different from で, which would normally mark the place where an action happens.
Because 書いてあります describes a state resulting from an action, に is the natural choice.

This is one of the most common questions learners have.

• 書いています can mean is writing or is written, depending on context
• 書いてあります specifically emphasizes that something has been written there intentionally and now remains in that state

So:

• ホワイトボードに書いています can sound more neutral or ambiguous
• ホワイトボードに書いてあります clearly suggests someone wrote it there on purpose, and it is there for people to see

That makes 書いてあります very natural for notices, schedules, instructions, and classroom information.

Because the thing being referred to is inanimate.

In Japanese:

• います is used for people and animals
• あります is used for things

In 書いてあります, the あります part matches the idea that the written content is a thing, not a person.

Also, in this pattern, 〜てあります is a set grammar form used with transitive verbs to show a deliberate resulting state.

It is often translated that way in English, but the nuance is a little different.

• 書かれています = passive-like it is written
• 書いてあります = it has been written there intentionally and remains there

So both can become is written in English, but 〜てあります often implies preparation or deliberate placement.

In a classroom, ホワイトボードに書いてあります suggests that the teacher or someone else wrote the key points there for a purpose.

Japanese often leaves out information that is obvious, unimportant, or easy to guess from context.

In this sentence, the writer/speaker probably does not need to say who wrote it, because it is not the main point. The important information is:

• the key points exist
• they are on the whiteboard

In English, we often feel a stronger need to mention the subject, but Japanese frequently omits it.

It is modifying 授業.

So the structure is:

• 今日の授業 = today’s lesson
• 今日の授業のポイント = the key points of today’s lesson

It does not mean today’s points of the lesson as a separate idea. The most natural grouping is:

• [今日の授業] の [ポイント]

Yes, that is possible, but the nuance changes a little.

• ポイントは makes the key points the topic: As for the key points of today’s lesson, they’re written on the whiteboard.
• ポイントが would focus more directly on the key points as the thing that is written there

In many contexts, は sounds more natural because the speaker is introducing or talking about that topic.

Because Japanese is basically an SOV language, which means the verb usually comes at the end.

So the order is often:

• topic / subject
• place / object / other information
• verb

Here:

• 今日の授業のポイントは = topic
• ホワイトボードに = location
• 書いてあります = verb phrase

This end-of-sentence verb placement is one of the biggest word-order differences from English.

Yes, it is polite but ordinary.

The ending あります is polite, so this sounds natural in situations like:

• a teacher speaking to students
• an announcement
• written instructions
• school or office communication

A more casual version might be:

• 今日の授業のポイントはホワイトボードに書いてある

That would be less polite and more conversational.