kousikisaito wo mite, asita no kaigi ha tyuusi da to sirimasita.

見て is the て-form of 見る.

Here it connects two actions:

• 公式サイトを見て = after looking at / by looking at the official website
• 知りました = I learned / found out

So the sentence flows as:

• I looked at the official website, and then I found out...

Using 見ます would not connect naturally here, and 見た would need a different structure, such as 見たあとで.

Because 見る normally takes a direct object, and を marks that object.

• 公式サイトを見て = looking at the official website

A native English speaker may wonder about で, since English often says on the website. But in Japanese, the website is what you are directly looking at, so を is the natural choice with 見る.

This is a noun phrase:

• 明日 = tomorrow
• の = links nouns, similar to 's or for
• 会議 = meeting

So:

• 明日の会議 = tomorrow's meeting / the meeting tomorrow

Here, の shows that 明日 is modifying 会議.

は marks 明日の会議 as the topic inside the quoted content:

• 明日の会議は中止だ = as for tomorrow's meeting, it is canceled

This does not necessarily mean strong contrast, though は can sometimes imply it. Here it mainly presents tomorrow's meeting as the thing being talked about.

You could think of it as:

• Regarding tomorrow's meeting, it is canceled.

中止 is a noun-like word, so when it is used as the predicate in plain style, it usually needs the copula だ:

• 会議は中止だ = the meeting is canceled

This is especially important before と, because と is quoting a full statement.

So:

• 明日の会議は中止だ = a complete plain-form statement
• 明日の会議は中止だと知りました = I learned that tomorrow's meeting is canceled

Before quotation particle と, Japanese usually uses the plain form, not the polite form.

So even though the main sentence ends politely with 知りました, the quoted content stays plain:

• 中止だ
  • と
    • 知りました

This is very common in Japanese:

• ～と思います
• ～と言いました
• ～と知りました

The outer sentence can be polite, while the quoted sentence remains plain.

と marks the content that was learned or found out.

So:

• 明日の会議は中止だ = the information
• と知りました = learned/found out that ...

In other words, と works like that in English:

• I learned that tomorrow's meeting is canceled.

Because 知る here means to come to know, to learn, or to find out.

So 知りました means:

• I found out
• I learned

The past tense refers to the moment of gaining the information.

This is different from English, where I know often describes the result. In Japanese:

• 知っています = I know
• 知りました = I found out / I learned

So this sentence is talking about the moment the speaker became aware of the cancellation.

Japanese often omits the subject when it is obvious from context.

Here, 知りました strongly suggests the speaker is the one who learned the information, so there is no need to say 私は.

A fuller version could be:

• 私は公式サイトを見て、明日の会議は中止だと知りました。

But in natural Japanese, leaving out 私は is very common.

It can suggest both connection and sequence, depending on context.

In this sentence, 公式サイトを見て、...知りました most naturally means:

• after looking at the official website, I found out...
• by looking at the official website, I found out...

So it is more than just two unrelated actions joined by and. It implies that looking at the website led to the knowledge.

They are similar, but not always identical in nuance.

• 中止 often means something is called off, canceled, or discontinued
• キャンセル is a loanword and often refers more specifically to canceling a reservation, booking, order, etc.

For a meeting, 中止 is very natural:

• 会議は中止だ = the meeting is canceled / called off

Japanese often puts background information first and the main verb at the end.

So the structure is roughly:

• 公式サイトを見て = after looking at the official site
• 明日の会議は中止だ = tomorrow's meeting is canceled
• と知りました = I learned that

Japanese builds up the sentence step by step, and the final verb often tells you the main action of the whole sentence.

Yes, that is a very natural English translation.

Even though the Japanese literally says something closer to:

• I looked at the official website and learned that tomorrow's meeting is canceled

in natural English, I saw on the official website that... often expresses the same idea well.

The Japanese sentence slightly emphasizes the process of checking the website and then finding out the information.