bānjiāgōngsī bùshì jīntiān lái, jiùshì míngtiān lái.

It means either...or....

So:

• 搬家公司不是今天来，就是明天来。
• The moving company is coming either today or tomorrow.

This pattern presents two possibilities, and the speaker believes one of them is true.

Not exactly. In this sentence, 不是 is part of the fixed pattern 不是A，就是B.

So here it does not simply mean a standalone not. Instead, the whole structure means:

• if not A, then B
• more naturally in English: either A or B

So 不是今天来，就是明天来 means:

• either they come today, or they come tomorrow

In this sentence, 就是 does not mean the basic to be meaning that beginners often learn first.

Here, 就是 is the second half of the pattern 不是……就是…….

So:

• 不是今天来，就是明天来
• literally: if it’s not today, then it’s tomorrow
• natural English: either today or tomorrow

So you should understand 就是 here as part of the grammar pattern, not as a simple is.

Because Chinese often repeats the verb in this kind of paired structure:

• 不是今天来，就是明天来

This makes both choices clear and balanced:

• 今天来
• 明天来

It sounds more natural and complete than leaving the second 来 out.

You can think of it like:

• either come today, or come tomorrow

Because 今天 and 明天 are time words, and in Chinese, time words usually come before the verb.

So:

• 今天来 = come today
• 明天来 = come tomorrow

This is very normal Chinese word order.

A simple pattern is:

• time + verb

For example:

• 我今天去。 = I’m going today.
• 他明天回来。 = He’ll come back tomorrow.

搬家公司 means moving company.

It is made up of:

• 搬家 = to move house / move home
• 公司 = company

So together:

• 搬家公司 = a company that helps people move

This is a very common word in everyday Chinese.

Yes, but only partly.

The speaker is not sure which day the moving company will come, but the speaker thinks it will be one of these two days:

• today
• tomorrow

So the sentence shows:

• uncertainty about the exact choice
• but certainty that one of the two choices is correct

Not quite.

或者 simply means or and is often used for listing options more neutrally.

But 不是……就是…… usually sounds more like:

• it must be one or the other
• if not this, then that

So in this sentence, 不是今天来，就是明天来 feels a bit stronger and more specific than just using 或者.

Compare:

• 今天或者明天来 = come today or tomorrow
• 不是今天来，就是明天来 = either today or tomorrow; one of those two

The second one emphasizes the two-way choice more clearly.

Because Chinese often does not need a special future marker when the time is already clear.

Here, 今天 and 明天 already show the time, so 来 can naturally refer to a present or future event depending on context.

So:

• 今天来
• 明天来

already clearly tell us when the action will happen.

You could sometimes add 会 in other sentences, but it is not necessary here.

In careful dictionary form, it is written bùshì.

But in normal speech, when 不 comes before a fourth-tone syllable like 是 (shì), 不 usually changes from fourth tone to second tone.

So it is commonly pronounced:

• bú shì

This is a very important pronunciation rule in Mandarin.

So although you often see bùshì in pinyin, you will usually hear:

• búshì

Yes. The comma is often used to make the sentence easier to read, but it is not always necessary.

So both of these are fine:

• 搬家公司不是今天来，就是明天来。
• 搬家公司不是今天来就是明天来。

The comma just helps show the pause between the two alternatives.

Yes. That is a very natural English translation.

A few natural English versions are:

• The moving company is coming today or tomorrow.
• The moving company is coming either today or tomorrow.
• If not today, then tomorrow, the moving company will come. — this is closer to the Chinese structure, but less natural in everyday English

So for normal English, either today or tomorrow is usually the best match.