Він обдурює людей.

Yes, it can often be left out if the subject is already clear from context.

Ukrainian frequently drops subject pronouns when they are not needed:

• Він обдурює людей. = neutral, explicit he
• Обдурює людей. = is deceiving people / deceives people, if the listener already knows who you mean

One important detail: the verb form обдурює shows 3rd person singular, but it does not show gender in the present tense. So without він, the sentence could mean he or she, depending on context.

Обдурює is the 3rd person singular present tense form of the imperfective verb обдурювати.

So:

• обдурювати = infinitive
• обдурює = he/she deceives, is deceiving

The ending -є is a normal present-tense ending for this verb in the he/she/it form.

It can mean either one.

In Ukrainian, the present tense often covers both:

• a habitual meaning: he deceives people
• an ongoing right now meaning: he is deceiving people

Context tells you which is meant.

Because обдурює is imperfective, it focuses on the action as a process, repeated action, or general fact, rather than a single completed result.

This is an aspect difference.

• обдурювати = imperfective

  • ongoing, repeated, habitual
  • Він обдурює людей. = He deceives people / He is deceiving people.

• обдурити = perfective

  • one completed action, with a result
  • Він обдурив людей. = He deceived the people / He tricked people.
  • Він обдурить людей. = He will deceive people.

A perfective verb normally does not have a true present meaning in Ukrainian. Its “present-looking” forms usually refer to the future.

Because людей is the correct form for people as a direct object here.

The dictionary form is:

• люди = people

But in this sentence, people is the thing receiving the action, so it must go into the accusative case.

With animate plural nouns in Ukrainian, the accusative plural usually looks the same as the genitive plural. That is why you get:

• люди → людей

So:

• люди = people
• Він обдурює людей. = He deceives people

Here it is accusative by function, even though it has the same form as the genitive plural.

That is a very common pattern in Ukrainian:

• for animate plural nouns, the accusative form matches the genitive form

So in this sentence:

• function: direct object → accusative
• shape/form: looks like genitive plural → людей

You can think of it as:

• syntactically accusative
• morphologically identical to genitive plural

There is no article because Ukrainian does not have articles like English a/an and the.

So людей can mean:

• people
• the people
• some people

The exact meaning depends on context.

That is very normal in Ukrainian. You usually understand definiteness from the situation, not from a separate word.

No, Ukrainian word order is fairly flexible.

Він обдурює людей. is the most neutral order here:

• subject + verb + object

But other orders are possible, with different emphasis:

• Людей він обдурює. = emphasizes people
• Обдурює він людей. = more marked; can sound contrastive or stylistic

So the sentence order can change, but the neutral, standard version is the one you were given.

The stress is:

• Він обдурю́є люде́й.

A rough English-style guide is:

• vin ob-du-RYU-ye lyu-DEY

A few useful points:

• ю in обдурює sounds like yu
• ює is pronounced as two parts: yu-ye
• людей has the stress on the last syllable: -дей

It is a normal, everyday verb.

обдурювати / обдурити means to deceive, trick, fool, cheat someone, depending on context. It is not especially formal or literary.

It often suggests that someone is making others believe something false or taking advantage of them in a dishonest way.

So this sentence sounds natural and ordinary Ukrainian, not overly formal.