Learn Hardcore Chinese: míngtiān wǒmen tíqián shí fēnzhōng chūfā, jiù bú huì chídào le. - Tomorrow we'll set off ten minutes early, then we won't be late.

明天我们提前十分钟出发，就不会迟到了。 = If we leave 10 minutes early tomorrow, then we won’t be late.
You can optionally add 如果/要是 before the first clause: 如果明天我们提前十分钟出发，就不会迟到了。
就 also adds a feeling of straightforwardness/immediacy: do A, then B naturally follows.

Why is 不 (bù) pronounced bú in 不会 (bú huì)?

Tone sandhi: 不 (bù) changes to the second tone (bú) when it comes before a fourth-tone syllable.

不会 bú huì, 不对 bú duì, 不要 bú yào
Otherwise it stays bù: 不高 bù gāo, 不忙 bù máng, 不好 bù hǎo
As a stand-alone exclamation, it’s bù: 不！

What does 会 (huì) mean here? “Can” or “will”?

Here 会 means “will”/“be likely to,” expressing prediction or likelihood, not ability.

Ability: 我会游泳 (I can/know how to swim).
Prediction: 明天会下雨 (It will likely rain tomorrow), 我会迟到 (I will be late).
In the sentence, 不会迟到 = will not be late.

What’s the purpose of the sentence-final 了 (le) in 就不会迟到了?

This is sentence-final 了 (change-of-state/“new situation” 了). It signals that a situation will change as a result.

就不会迟到了 = then we won’t be late anymore / that solves the lateness problem.
Without 了 (就不会迟到) is also fine; it’s just more neutral, with less “new state” feeling.

Why 不 and not 没 for negation?

不 is for habitual, general, or future negation: 明天不会迟到 (won’t be late tomorrow).
没(有) is for past/completed events: 我今天没迟到 (I wasn’t late today).
For prohibitions, use 别: 别迟到 (don’t be late).

Can I drop 就 and say …，不会迟到了?

It’s better to keep 就 to show cause-result. Without 就, the link feels weaker. Natural alternatives:

明天我们提前十分钟出发，这样就不会迟到了。
明天我们提前十分钟出发，那(么)就不会迟到了。

Can I omit 会 and say 就不迟到了?

Yes. Both are natural:

就不迟到了 (a bit more categorical)
就不会迟到了 (explicitly predictive/likely) Examples: 早点出门就不堵车了 / 就不会堵车了. Both are common.

What exactly does 提前 (tíqián) mean here, and how does it work with another verb?

提前 means “to move earlier than the scheduled/expected time.” In 提前十分钟出发, 提前十分钟 works adverbially to modify 出发.

Pattern: 提前 + duration + V: 我们提前二十分钟开始。
As a verb: 把会议时间提前十分钟; 出发时间提前了十分钟.
It implies “earlier than planned/usual,” even if the reference isn’t stated.

Where should 十分钟 go? Is 十分钟提前出发 okay?

Use 提前十分钟出发. Putting the duration after 提前 is the standard pattern.

Correct: 我们提前十分钟出发.
Also correct: 我们把出发时间提前十分钟; 出发时间提前了十分钟.
十分钟提前出发 is unnatural in this context.

How else could I say the same idea?

Some natural rephrasings:

明天我们把出发时间提前十分钟，这样就不会迟到了。
(Less specific) 明天我们早点儿出发，就不会迟到了。
With destination: 明天我们提前十分钟去机场，就不会迟到了。
With outcome verb: 明天我们提前十分钟出发，就来得及了/就赶得上了。

Why does the sentence start with 明天? Could I say 我们明天提前十分钟出发?

Both are fine.

明天我们… puts the time in topic position for emphasis.
我们明天… is also very common. Chinese often places time expressions before the verb, either before or after the subject: 明天我们… / 我们明天….

What’s the difference among 出发, 走, and 离开 here?

出发: set off/depart (planned trip or route). Most fitting here.
走: go/leave (casual). 我们早点走 feels more colloquial.
离开: leave a place, emphasizes separation: 离开学校. Not as natural for scheduling a start time for a trip.

Could I use 才 instead of 就 (…，才不会迟到)?

You can, but the meaning shifts.

…，就不会迟到: do A, and the result B follows (plain cause-effect).
…，才不会迟到: only if A happens will B not happen; it stresses necessity. It can imply that without leaving early, being on time is unlikely.

Is the comma and the implied “if” okay? Do I need 如果?

Yes, it’s standard to omit 如果 and just use 就 to show the conditional.

With it: 如果/要是/只要明天我们提前十分钟出发，就不会迟到了。
Without it (as given) is very natural in speech and writing.

Does 分钟 take a classifier like 个? Is 十个分钟 correct?

No classifier is used. Say 十分钟, not 十个分钟 and not 十分钟钟.

Duration: 十分钟.
Clock time: 十点十分 (ten ten), not 十点十分钟 in clock-reading.

Can I use 不晚/不会晚 instead of 不会迟到?

Sometimes, but nuance differs.

迟到 specifically means “be late (for an appointment/class/meeting).”
晚/晚了 is broader: 我来晚了 (I arrived late). 不会晚 can sound less precise and may mean “it won’t be late (in the day)” or “we won’t arrive late,” depending on context.
For formal punctuality, 不(会)迟到 is clearest.

What exactly is 迟到? Can I say 迟到十分钟?

迟到 is a verb meaning “to be late.” You can quantify it:

他迟到十分钟 or 他迟到了十分钟 (he was 10 minutes late).
Prediction: 我们会迟到十分钟 (we’ll be 10 minutes late).
Your sentence prevents that: 提前十分钟出发，就不会迟到(了).

Do I need to repeat 我们 in the second clause?

No. The subject is understood to be the same.

Given: 明天我们提前十分钟出发，就不会迟到了。
Repeating is possible but wordier: 明天我们提前十分钟出发，我们就不会迟到了。

How do I make this sound like a suggestion (“Let’s…”)?

Add 吧, or use 这样 to present a plan:

明天我们提前十分钟出发吧，这样就不会迟到了。
要不然 for proposing: 要不我们明天提前十分钟出发？这样就不会迟到了。

How would I ask, “If we leave ten minutes early tomorrow, will we still be late?”

Use the A-not-A form with 会不会:

明天我们提前十分钟出发，会不会迟到？
Another way: 明天提前十分钟出发，够不够不迟到？ (more colloquial)

Does 提前 need an explicit reference point (earlier than what)?

Not necessarily. If no reference is stated, it’s understood as “earlier than originally planned/usual.”

Explicit: 比原计划提前十分钟出发.
Implicit (your sentence): the listener infers “earlier than our usual/previous plan.”