Người ác lừa họ.

Because in Vietnamese, adjectives usually come after the noun they describe.

So:

• người = person
• ác = evil, cruel, wicked

That makes người ác literally person evil. This is normal Vietnamese word order, even though English would say evil person.

By itself, it can be singular, plural, or generic, depending on context.

Vietnamese bare nouns are more flexible than English. For example:

• một người ác = one evil person
• những người ác = evil people

Without một or những, the sentence leaves that open. In real use, context tells you whether it means an evil person, the evil person, or evil people in general.

Vietnamese does not have articles in the same way English does.

That means a noun phrase like người ác can often work without anything equivalent to a/an/the. If a speaker wants to make one explicit, they can say một người ác. If they want plural, they can say những người ác.

So the lack of an article here is completely normal.

Yes, the basic structure here is Subject + Verb + Object, just like English:

• Người ác = subject
• lừa = verb
• họ = object

So the sentence pattern is very straightforward.

Ác is usually stronger than plain bad.

It often means:

• evil
• wicked
• cruel

So người ác is not just someone who is a little bad or unpleasant. It suggests a morally bad or harmful person.

If you wanted a weaker idea like bad person or not nice person, Vietnamese might use other words depending on context.

Lừa means to trick, to deceive, or to cheat.

In this sentence, it means that the subject is fooling or deceiving họ.

A very common related expression is lừa dối, which also means deceive.
But lừa by itself is already a normal verb, so lừa họ is perfectly natural.

Yes. Vietnamese pronouns usually do not change form the way English pronouns do.

So:

• họ can mean they
• họ can also mean them
• họ can also mean their, depending on position

In this sentence, họ comes after the verb lừa, so it is the object, which makes it them.

Vietnamese often leaves tense unmarked if the time is clear from context.

So lừa by itself does not tell you whether the action is present, past, or future. The sentence could be understood in different ways depending on the situation.

If needed, Vietnamese can add markers such as:

• đã for past
• đang for ongoing action
• sẽ for future

For example:

• Người ác đã lừa họ = the evil person deceived them
• Người ác đang lừa họ = the evil person is deceiving them
• Người ác sẽ lừa họ = the evil person will deceive them

A few parts are especially important:

• người: starts with ng, like the end of English sing, but at the beginning of the word
• ác: has the sắc tone, which rises
• lừa: has the huyền tone, which falls
• họ: has the nặng tone, which is low and short, often with a stopped quality

Two vowels may feel unfamiliar to English speakers:

• ư in lừa
• ươ in người

Those do not have exact English equivalents, so they usually take practice.

It is grammatical and understandable, but the most natural choice can depend on context.

Possible alternatives include:

• Kẻ ác lừa họ = more literary or dramatic, like the villain deceives them
• Người xấu lừa họ = a less intense idea, more like bad person
• Bọn xấu lừa họ = the bad guys trick them

So người ác is fine, but native speakers might choose a different noun phrase depending on style, tone, and context.