Кажется, дождь вот-вот начнётся.

Here Кажется is an impersonal word meaning something like it seems, apparently, or looks like.

It comes from the verb казаться meaning to seem / to appear.

In this sentence, it does not need an explicit subject. Russian often says simply Кажется, ... where English would usually say It seems ...

A related fuller version is:

• Мне кажется, дождь вот-вот начнётся. = It seems to me that the rain is about to start.

So Кажется here adds uncertainty or personal impression.

Because Кажется is being used as a parenthetical introductory word, not as the main verb of the sentence.

It functions like apparently or it seems in English, commenting on the whole statement. In Russian, such introductory words are often separated by commas.

So:

• Кажется, дождь вот-вот начнётся.

means something like:

• It seems, the rain is about to start
• more naturally in English: It seems the rain is about to start

If казаться were used as a normal verb inside the sentence, the punctuation would be different.

Because дождь is the subject of начнётся.

The sentence is literally structured like:

• The rain
  • will begin

So дождь stays in the nominative.

This is different from some English weather expressions, where English often uses a dummy subject like it:

• It is raining
• It looks like it will rain

Russian often just uses the weather noun itself:

• Идёт дождь = Rain is falling / It is raining
• Дождь начнётся = The rain will start

Вот-вот is an idiomatic expression meaning:

• any moment now
• about to
• on the verge of

It gives a strong sense that something is imminent.

So:

• дождь вот-вот начнётся

means not just the rain will start soon, but more specifically the rain is just about to start.

Compare:

• скоро начнётся = will start soon
• вот-вот начнётся = will start any second now

The repetition in вот-вот is just part of the fixed expression.

Because начнётся is a perfective future form, and that fits the meaning here.

• начинается = is beginning / begins
• начнётся = will begin

Since the rain has not started yet, but is about to start, Russian uses the future form.

Also, the perfective verb is important here because the sentence focuses on the starting point of the rain as a single event.

Compare:

• Дождь начинается. = The rain is beginning.
• Дождь начнётся. = The rain will begin.

With вот-вот, начнётся is especially natural because the idea is that the beginning is imminent.

Because the verb here is начаться, not начать.

This is a very important distinction:

• начать = to start something
• начаться = to start / to begin as an event

So:

• Я начал урок. = I started the lesson.
• Урок начался. = The lesson started.

In your sentence, the rain is not starting some object. The rain itself is beginning as an event, so Russian uses начаться:

• дождь начнётся

This -ся form often corresponds to English begin rather than start something.

Because Russian does not use dummy subjects as much as English does.

In English, we often need it even when it does not refer to anything concrete:

• It seems...
• It is raining
• It is getting dark

Russian often does not need that placeholder.

So instead of saying It seems, Russian can simply say:

• Кажется

And instead of It’s about to rain, Russian can talk directly about the rain:

• Дождь вот-вот начнётся

This is a very common difference between English and Russian sentence structure.

Yes.

• скоро начнётся means it will start soon
• вот-вот начнётся means it will start any moment now

So вот-вот sounds more immediate and more vivid.

For example:

• Фильм скоро начнётся. = The film will start soon.
• Фильм вот-вот начнётся. = The film is about to start right now.

In your sentence, вот-вот suggests the speaker can already see signs that the rain is imminent.

Yes. Russian word order is flexible, though not completely free.

Your sentence:

• Кажется, дождь вот-вот начнётся.

is natural and neutral.

Other possible orders include:

• Дождь, кажется, вот-вот начнётся.
• Вот-вот начнётся дождь.

The basic meaning stays similar, but the emphasis changes:

• Кажется first gives the speaker’s impression right away
• дождь first puts the rain in focus
• вот-вот first emphasizes the immediacy

So the original order is a very good standard version, but alternatives are possible.

Because in everyday Russian writing, ё is often written as е.

So these are the same word:

• начнётся
• начнется

But the pronunciation is still with ё, not plain е.

That means the stress is on that syllable:

• начнётся

For learners, seeing the ё is very helpful, because it makes both the pronunciation and the stress clear.

The stress pattern is:

• Ка́жется, дождь вот-во́т начнётся.

A rough pronunciation guide:

• Ка́жется ≈ KAH-zhit-suh
• дождь ≈ doshd' with a soft final consonant
• вот-вот ≈ vot-VOT
• начнётся ≈ nuch-NYOT-suh

A couple of useful notes:

• ё is always stressed
• дождь can be tricky because of the consonant cluster
• -тся / -ться in verbs is pronounced -tsa

So начнётся sounds like nach-NYOT-sa, not like it is written letter by letter.