kono sisetu ha kodomotati wo ukeiremasu.

この is a demonstrative determiner, meaning this when it directly modifies a noun.

So:

• この施設 = this facility
• この must be followed by a noun
• it does not take a particle like は or の between it and the noun

Compare:

• この施設 = this facility
• これは施設です = this is a facility

In your sentence, この is simply describing 施設.

The particle は is normally written with the hiragana は, but when it is used as the topic particle, it is pronounced わ.

So in:

• この施設は
  you say kono shisetsu wa

This is one of the standard spelling/pronunciation differences in Japanese particles, similar to:

• へ being pronounced e as a particle
• を being pronounced o as a particle

は marks the topic of the sentence.

In:

• この施設は子供たちを受け入れます。

the topic is この施設 = this facility.

A natural way to understand it is:

• As for this facility, it accepts/admits children.

So は does not exactly mean is or does. It tells you what the sentence is about.

を marks the direct object of the verb.

The verb here is 受け入れます = accepts / admits / takes in.
So the thing being accepted is 子供たち.

That gives:

• 子供たちを受け入れます = accepts/admits children

A very literal breakdown is:

• この施設は = as for this facility
• 子供たちを = children (object)
• 受け入れます = accepts / admits

たち often adds a plural or group sense, so 子供たち means children.

However, Japanese does not mark plural the same way English does. In many cases, a noun can be singular or plural depending on context.

So:

• 子供 can mean a child or children, depending on context
• 子供たち makes the plural/group meaning clearer

In this sentence, 子供たち emphasizes that the facility accepts children as a group, not just one child.

Yes, it could.

• この施設は子供を受け入れます。
• この施設は子供たちを受け入れます。

Both can be natural, depending on context.

The version with たち sounds more explicitly plural: children.
The version without たち can still mean children in Japanese, because number is often left unstated unless it matters.

So 子供たち is not wrong at all—it just makes the plural meaning more obvious.

受け入れます is the polite non-past form of 受け入れる.

Its core meaning is something like:

• to accept
• to admit
• to take in
• to receive

In this sentence, it most likely means the facility accepts or admits children, for example as residents, participants, students, or people under care, depending on context.

It does not usually mean physically receiving an object like a package. It often has the nuance of allowing someone in, taking responsibility for them, or accepting them into a system or institution.

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

So the structure here is:

• この施設は = topic
• 子供たちを = object
• 受け入れます = verb

This is a very common Japanese word order pattern:

• Topic + object + verb

English speakers often expect the verb earlier, but in Japanese it is very natural for the sentence to build up and then end with the action.

It can be present or future, depending on context.

Japanese non-past forms often cover both:

• present habitual: this facility accepts children
• future: this facility will accept children

Without more context, the sentence is usually understood as a general fact:

• This facility accepts children.

Yes. It uses the ます-form:

• 受け入れます

That makes it polite and appropriate for normal conversation, writing, explanations, brochures, announcements, and so on.

It is not extremely formal, but it is more polite than the plain form:

• 受け入れる

So:

• この施設は子供たちを受け入れる。 = plain / less polite
• この施設は子供たちを受け入れます。 = polite

Japanese does not have articles like a, an, or the.

So:

• 施設 can mean a facility, the facility, or just facility, depending on context

In this sentence, この already specifies it clearly:

• この施設 = this facility

Because of that, no extra word like the is needed.

Good question. You may see several spellings:

• 子供
• 子ども
• sometimes こども

All can refer to child/children.

Many modern writers and educational materials prefer 子ども, partly because it avoids the older kanji 供, which historically has other associations. But 子供 is still very common and widely understood.

So in your sentence, 子供たち is perfectly normal Japanese.

No—normal Japanese writing usually does not use spaces between words.

So this would normally be written as:

• この施設は子供たちを受け入れます。

The spaced version is often used in beginner materials to make the parts easier to see:

• この / 施設 / は / 子供たち / を / 受け入れます

It is a learning aid, not standard native writing.