syusaisya ga sankamousikomi wo yomu.

A natural reading is:

主催者 = しゅさいしゃ
が = が
参加申込 = さんかもうしこみ
を = を
読む = よむ

So the whole sentence is:

しゅさいしゃ が さんかもうしこみ を よむ。
Romanized: Shusai-sha ga sanka mōshikomi o yomu.

Also, を is pronounced o in modern Japanese.

が marks the grammatical subject of the sentence.

Here, 主催者が tells you that the organizer is the one doing the action of reading.

So the structure is:

• 主催者 = organizer
• が = subject marker
• 参加申込 = application / registration
• を = object marker
• 読む = read

In other words, the organizer is the doer of 読む.

This is a very common question.

Both が and は can appear after a noun, but they do different jobs:

• が marks the subject
• は marks the topic

In this sentence, 主催者が参加申込を読む。, が presents the organizer as the one who reads it.

If you changed it to 主催者は参加申込を読む。, the meaning would be closer to:

• As for the organizer, they read the application
• or it may sound contrastive, depending on context

So:

• 主催者が = the organizer is the one who reads it
• 主催者は = as for the organizer, they read it

For a simple standalone sentence, が is perfectly natural.

を marks the direct object, meaning the thing that the action is done to.

Here, the action is 読む = to read, and the thing being read is 参加申込.

So:

• 参加申込を読む = read the application / registration

A useful shortcut is:

• が = who does it
• を = what is affected by the action

Because Japanese normally puts the verb at the end of the sentence.

A basic Japanese word order is:

subject + object + verb

So this sentence follows the common pattern:

主催者 が 参加申込 を 読む。
subject + object + verb

In English, you would say The organizer reads the application.
In Japanese, it is more like Organizer subject-marker application object-marker reads.

The particles が and を show each word’s role, so word order is more flexible than in English, but the verb usually stays at the end.

読む is the plain, dictionary form, also called the non-past form.

In Japanese, the non-past can mean either:

• reads
• will read

The exact meaning depends on context.

So this sentence could mean:

• The organizer reads the application
• The organizer will read the application

If you wanted the polite form, it would be:

主催者が参加申込を読みます。

It is a compound noun:

• 参加 = participation
• 申込 = application / sign-up / registration

Together, 参加申込 means something like:

• application to participate
• registration
• sign-up

Depending on context, it can refer to the application itself, the registration information, or the act of applying.

If you specifically want to say application form as a physical document, Japanese often uses:

参加申込書 = participation application form

So 参加申込 is understandable, but 参加申込書 is more explicit if you mean an actual form or paper.

Good observation.

The noun is very often written as:

• 申し込み
• 申込み

But in signs, forms, headings, and compact written style, you will also often see shortened kanji-heavy forms like:

• 申込
• 参加申込

So 申込 is not strange, but it is a more compressed written style.

The reading is still basically もうしこみ.

Japanese does not have articles like English the and a.

That means a noun like 主催者 can mean:

• the organizer
• an organizer

And 参加申込 can mean:

• the application
• an application
• registration
• the registration

Context tells you which one is meant.

So Japanese often leaves this kind of information unstated unless it is important.

No. Normal Japanese writing usually does not use spaces between words.

So this would normally be written as:

主催者が参加申込を読む。

Spaces are often added in learning materials to make the structure easier to see.

It is written with the kana を, which is historically associated with wo, but in modern standard Japanese it is usually pronounced o.

So in this sentence:

参加申込を読む

you would say:

さんかもうしこみ お よむ

not ... wo yomu in normal pronunciation.

In romanization, you may still see it written as wo, but the actual sound is usually just o.