tonari no hito ha totemo sinsetu de, komatta toki ha tasukete kuremasu.

隣の人 means the person next door or the person nearby, depending on context.

• 隣 = next to, neighboring
• 人 = person
• 隣の人 = the person who is next to me/us

In many everyday situations, this often means the neighbor.

の connects nouns and shows that one noun describes another.

So:

• 隣 = next door / neighboring
• 隣の人 = the neighboring person / the person next door

You can think of の here as working a bit like of or like an adjective-forming connector, though in natural English we would not translate it literally.

は marks the topic of the sentence.

So 隣の人は means:

• As for the person next door...
• The person next door, ...

It tells you what the sentence is about. It does not necessarily mean the same thing as the English subject every time, though here it feels similar.

親切 is a na-adjective.

It means kind or helpful.

That is why you may see forms like:

• 親切な人 = a kind person
• 親切です = is kind
• 親切で = being kind / and kind

Unlike i-adjectives, na-adjectives need special endings depending on how they are used.

親切で is the te-form-like connecting form of the na-adjective 親切.

It connects this idea to the next part of the sentence:

• とても親切で、困ったときは助けてくれます
• They are very kind, and when I’m in trouble, they help me.

So で here means something like:

• and
• being
• and also

If the sentence ended there, you would say 親切です. But because the sentence continues, 親切で is used to connect.

とても means very.

So:

• とても親切 = very kind

It simply strengthens the adjective.

This is a very common pattern in Japanese.

When a clause comes before とき and modifies it, the tense shows the state at that time.

• 困る = to be troubled / to be in trouble
• 困ったとき = when someone was/is in trouble, or more naturally, when someone is in trouble

Even though 困った looks like a past form, in this pattern it often refers to the situation that has happened by the time of that moment.

Compare:

• 困るとき = when one gets into trouble / when trouble occurs
• 困ったとき = when one is in trouble / when trouble has already come up

In many beginner contexts, it is best understood simply as when I’m in trouble.

とき means time or when.

So:

• 困ったとき = when in trouble
• 困ったときは = as for when I’m in trouble / when I’m in trouble

The は after とき marks that whole time-expression as the topic or contrastive frame.

It gives the nuance of:

• When I’m in trouble, ...
• At times when I’m in trouble, ...

Because they mark two different topics/frames:

1. 隣の人は
   → the main topic: as for the person next door

2. 困ったときは
   → a secondary topic or time frame: when I’m in trouble

So the sentence is structured like:

• As for the person next door, when I’m in trouble, they help me.

Japanese often uses multiple は particles like this, especially when one marks the main topic and another marks a time, place, or contrastive phrase.

This is a very important point.

• 助けます = help
• 助けてくれます = do the favor of helping me/us

The verb くれる is used when someone does something for the speaker or someone close to the speaker.

So 助けてくれます has the nuance:

• they help me
• they kindly help me out

It sounds more natural here because the sentence is describing the neighbor’s kindness toward the speaker.

The person being helped is not stated directly, but because of くれます, it is understood to be:

• me
• us
• someone in the speaker’s in-group

So the sentence naturally suggests:

• The person next door is very kind and helps me when I’m in trouble.

If it were just 助けます, the beneficiary would be less clearly tied to the speaker.

Yes. Japanese often leaves subjects unstated when they are clear from context.

In this sentence, 困ったとき most naturally means:

• when I’m in trouble
• sometimes when we’re in trouble

Because the following phrase is 助けてくれます, the speaker is probably the one receiving help, so the hidden subject inside 困ったとき is usually the speaker.

Yes. A casual version would be:

隣の人はとても親切で、困ったときは助けてくれる。

Changes:

• くれます → くれる

That makes the sentence plain/casual instead of polite.

Everything else can stay the same.

It breaks down like this:

• 隣の人は = as for the person next door
• とても親切で、 = is very kind, and...
• 困ったときは = when I’m in trouble
• 助けてくれます。 = helps me / does me the favor of helping

So the pattern is:

Topic + description + time frame + action

This is a very common Japanese sentence structure.