Người này rất ác.

In Vietnamese, adjectives can often work directly as the predicate, so you do not need a verb like to be.

So:

• Người này rất ác = This person is very cruel/evil
• literally: person this very cruel

This is completely normal Vietnamese sentence structure.

Using là here would usually be incorrect:

• Người này là rất ác ❌
• Người này rất ác ✅

Người này means this person.

Breakdown:

• người = person
• này = this

A very important pattern in Vietnamese is that demonstratives usually come after the noun:

• người này = this person
• người đó = that person
• nhà này = this house

So unlike English, Vietnamese says something more like person this.

Rất means very.

So:

• Người này ác = This person is cruel/evil
• Người này rất ác = This person is very cruel/evil

It goes before the adjective:

• rất ác = very cruel / very evil

This is a very common pattern:

• rất tốt = very good
• rất đẹp = very beautiful
• rất khó = very difficult

Ác usually means something like cruel, evil, wicked, or vicious. It is fairly strong.

Depending on context, Người này rất ác could mean:

• This person is very cruel.
• This person is very evil.
• This person is really vicious.

It is usually stronger than just mean in everyday English. If you only want to say someone is unpleasant or not nice, Vietnamese often uses softer expressions such as:

• xấu tính = bad-tempered / nasty in personality
• khó chịu = unpleasant / annoying
• tệ = bad

So ác is a strong negative word.

Normally, no.

In Vietnamese, là is mainly used to link one noun to another noun, like A is B in the sense of identity or category:

• Anh ấy là bác sĩ = He is a doctor
• Đây là bạn tôi = This is my friend

But with adjectives like ác, Vietnamese usually does not use là:

• Người này ác ✅
• Người này rất ác ✅
• Người này là ác ❌

So for descriptions with adjectives, just put the adjective after the subject.

It is grammatical and natural in the right context, but it can sound a bit detached, blunt, or even rude depending on tone and situation.

Người này is often used when:

• pointing someone out
• talking about someone nearby
• speaking in a somewhat impersonal way

If you know the person, Vietnamese often prefers a pronoun or relationship term, such as:

• anh ấy = he / that man
• cô ấy = she / that woman
• ông ấy, bà ấy, bạn ấy, etc.

So Người này rất ác is fine, but in real conversation it may sound like:

• This person here is very cruel with a somewhat direct or judgmental feel.

That is just the normal Vietnamese word order for demonstratives like this and that.

English:

• this person
• that house

Vietnamese:

• người này = person this
• nhà đó = house that

So the noun comes first, and words like này, đó, and kia usually come after it.

This is a very common thing English speakers need to get used to.

A rough pronunciation guide:

• Người: somewhat like ngwee-uhy said as one syllable, with a low/falling tone
• này: roughly nai with a falling tone
• rất: roughly zut or rut depending on accent, with a sharp rising tone and a clipped ending
• ác: roughly ak with a rising tone and clipped ending

A few notes:

• ng at the start of người is like the ng in sing, but at the beginning of the syllable
• r is pronounced differently in different regions
• final t and c are unreleased/stopped, so rất and ác end very sharply

Tone matters a lot here:

• người has a huyền tone
• này has a huyền tone
• rất has a sắc tone
• ác has a sắc tone

Yes.

• Người này ác = This person is cruel/evil
• Người này rất ác = This person is very cruel/evil

Leaving out rất makes the statement less intense. Both are natural.

Vietnamese often omits degree words when the context already makes the strength clear.

Yes, and that changes the meaning slightly:

• người này = this person
• người đó = that person
• người kia = that person over there / that other person

So:

• Người này rất ác = This person is very cruel.
• Người đó rất ác = That person is very cruel.
• Người kia rất ác = That person over there is very cruel.

The exact feeling of đó and kia can vary a bit by context and region, but that is the basic idea.

Yes, usually it is.

Calling someone rất ác is quite strong. It suggests serious cruelty or wickedness, not just mild rudeness.

So this sentence would usually fit contexts like:

• someone harms others
• someone behaves heartlessly
• someone is morally bad in a serious way

If you want something softer, you might say:

• Người này không tốt = This person is not good
• Người này xấu tính = This person has a bad personality
• Người này hơi khó chịu = This person is kind of unpleasant

So learners should be careful: ác is not a mild everyday insult.

The pattern is:

Subject + degree word + adjective

In this sentence:

• Người này = subject
• rất = degree word
• ác = adjective

So:

• Người này rất ác

You can use the same pattern with many other adjectives:

• Người này rất tốt = This person is very good.
• Người này rất hiền = This person is very gentle/kind.
• Người này rất thông minh = This person is very intelligent.

This is one of the most useful Vietnamese sentence patterns to learn early.