búyào shānghài biéren.

This is because of a very common pronunciation rule in Mandarin called tone sandhi.

• 不 is normally fourth tone: bù
• But when 不 comes right before another fourth-tone syllable, it changes to second tone: bú

So:

• 不
  • 要 yào → búyào

You still write 不, but you pronounce it bú here.

不要 can mean different things depending on context.

In this sentence, it means:

• don’t ...
• must not ...
• should not ...

So here it is used to give a warning, instruction, or prohibition.

Even though 要 often means to want or to need, the combination 不要 very often means don’t when telling someone not to do something.

For example:

• 不要说话。 = Don’t talk.
• 不要担心。 = Don’t worry.

So in 不要伤害别人, 不要 introduces a negative command.

Yes, 别伤害别人 is natural too.

Both 不要 and 别 can mean don’t, but there is a small difference in style:

• 别 is usually more common in everyday spoken Mandarin
• 不要 can sound a little fuller, firmer, or slightly more formal depending on context

So:

• 别伤害别人。
• 不要伤害别人。

Both are correct and natural.

Very roughly:

• 别 = shorter, very conversational
• 不要 = also common, sometimes a bit more emphatic

Because this is an imperative sentence—a command or instruction.

In English, we also often leave out the subject in commands:

• Don’t hurt others.
• not You don’t hurt others in this meaning

Mandarin does the same thing. The understood subject is usually you.

So 不要伤害别人 really means something like:

• (You) don’t harm others.

The subject is omitted because it is obvious from context.

Here, 伤害 is a verb meaning:

• to harm
• to hurt
• to injure

It can refer to:

• physical harm
• emotional harm
• general damage to a person

So it is broader than just physical injury.

Examples:

• 他的话伤害了我。 = His words hurt me.
• 不要伤害动物。 = Don’t harm animals.

In your sentence, 伤害 is the main verb.

别人 means:

• other people
• others
• sometimes someone else, depending on context

In this sentence, it means other people / others.

So 伤害别人 means to harm other people.

A useful thing to remember:

• 别 here is not the same as the command word 别 meaning don’t
• In 别人, it is part of one vocabulary word: 别人

So you should learn 别人 as a complete word.

Because Mandarin usually follows Subject + Verb + Object word order, just like English.

Here the structure is:

• 不要 = don’t
• 伤害 = harm
• 别人 = others

So literally, the order is:

• Don’t + harm + others

That is normal Mandarin sentence structure.

In many cases, yes.

Both can exist, but they are not exactly the same in feel:

• 伤害别人 sounds more complete and standard for harming others
• 伤别人 is less common in this broad moral sense

Why?

Because 伤害 is a set word meaning to harm/injure, including emotional or general harm.
By contrast, 伤 by itself often relates more directly to injure or wound, and it may sound less natural in this kind of general advice.

So for a sentence like Don’t harm others, 不要伤害别人 is a very natural choice.

It is commonly pronounced biéren, with the second syllable 人 often in a neutral tone in normal speech.

So you will often hear:

• biéren

rather than a strongly stressed rén.

This is common with many everyday two-syllable words in Mandarin: the second syllable may become lighter and less stressed in natural speech.

It can be either, depending on context and tone of voice.

不要伤害别人。 can sound like:

• a direct command
• a warning
• moral advice
• a serious request

For example:

• A parent teaching a child: advice or instruction
• A teacher speaking firmly: command
• A dramatic situation: strong warning

So the grammar itself allows several tones, and context decides how strong it sounds.

Yes. That is one of the most important things about 伤害.

It can describe:

• physical injury
• emotional hurt
• psychological harm
• general damage to someone

For example:

• 你这样说会伤害别人。 = Speaking like that will hurt others.
• 战争伤害了很多人。 = War harmed many people.

So in 不要伤害别人, the idea is broad: don’t hurt people in any harmful way, not only physically.

This is a very common pattern:

• 不要 + verb + object

It means:

• Don’t do ...

Examples:

• 不要说话。 = Don’t speak.
• 不要看手机。 = Don’t look at your phone.
• 不要打人。 = Don’t hit people.
• 不要伤害别人。 = Don’t harm others.

This is one of the most useful basic patterns in Mandarin for giving negative commands.

Yes, you can, but it feels slightly different.

• 别人 = others / other people
• 其他人 = other people, often a bit more explicit

In this sentence, 别人 sounds very natural and idiomatic.

Compare:

• 不要伤害别人。 = Don’t harm others.
• 不要伤害其他人。 = Don’t harm other people.

The second one is also correct, but 别人 is simpler and more common in this kind of general statement.