У ребёнка сильная личность.

Russian often expresses possession with the pattern:

у + person in the genitive + what is possessed

So:

У ребёнка сильная личность.
literally = At the child, there is a strong personality
natural English = The child has a strong personality.

This is a very common Russian structure. Instead of a verb like to have in ordinary statements, Russian usually prefers у меня есть..., у него..., у ребёнка..., and so on.

Because after у, Russian uses the genitive case.

The dictionary form is:

ребёнок = child

But after у, it becomes:

у ребёнка = of the child / with the child / the child has

So this is not a random change. It is a case ending required by the preposition у.

In the present tense, Russian often omits есть when it simply means is.

So instead of saying something like The child is a strong personality, Russian just says:

У ребёнка сильная личность.

Also, in possession structures, есть is often optional depending on emphasis and style.

Compare:

• У ребёнка сильная личность. = The child has a strong personality.
• У ребёнка есть сильная личность. = grammatical, but less natural here.

In this sentence, есть is usually left out because the point is to describe the child’s character, not just to state existence.

Because сильная must agree with личность.

личность is:

• feminine
• singular
• nominative

So the adjective must also be:

• feminine
• singular
• nominative

That gives:

• masculine: сильный
• feminine: сильная
• neuter: сильное

Since личность is feminine, we use сильная личность.

A useful clue is the ending. Many nouns ending in -ь are feminine, and личность is one of them.

You usually learn its gender from a dictionary or from experience with the word. In this case:

личность = a feminine noun

That is why the adjective is сильная.

Not exactly.

сильная личность usually means:

• a strong personality
• a strong-willed person
• someone with inner strength and character

It often refers more to character, force of personality, or psychological strength than to physical strength.

So У ребёнка сильная личность means the child has a powerful, well-defined, or strong character.

It does not usually mean the child is physically strong.

Literally, maybe, but in natural English that sounds unusual.

A better translation is:

• The child has a strong personality.
• The child is strong-willed.
• The child has a strong character.

Russian uses личность in a way that does not always match natural English word-for-word.

Yes, the word order can be changed, because Russian word order is more flexible than English word order.

The neutral version is:

У ребёнка сильная личность.

You might also hear:

Сильная личность у ребёнка.

That version gives more emphasis to сильная личность.

Even though the word order changes, the meaning stays roughly the same because the case endings show the grammatical roles.

Yes. ё is pronounced differently from е, and it is stressed here:

ребёнка = roughly ree-BYON-ka

Important points:

• ё is always stressed
• it sounds like yo
• in writing, Russians sometimes replace ё with е, but learners should remember the real pronunciation

So even if you see ребенка in some texts, it is still pronounced ребёнка.

It is singular.

• ребёнок = child
• ребёнка = of the child / the child’s / for the possession structure after у

The plural would be different:

• дети = children
• у детей = the children have

So:

У ребёнка сильная личность. = The child has a strong personality.
У детей сильные личности. = The children have strong personalities.

Yes, depending on context.

ребёнок is a general word meaning child, but it can sometimes also refer to a very young child or baby. In this sentence, the natural English translation is usually child.

Because the sentence talks about personality, it suggests a child old enough for that description to make sense.

Because it is the main noun being described.

In this possession pattern:

у + genitive possessor + nominative thing possessed

So:

• у ребёнка = possessor, in the genitive
• личность = thing possessed, in the nominative

And because сильная describes личность, it is also nominative feminine singular.

Yes, it is very similar, but there is a slight nuance.

• сильная личность emphasizes the child as a person with a powerful or distinct personality
• сильный характер emphasizes strong character, firmness, will, or toughness

Both are good Russian, and both can often be translated naturally as The child has a strong personality/character. The difference is subtle and depends on context.

Yes, it is natural.

It sounds like something someone might say when describing a child who is:

• independent
• determined
• hard to influence
• very self-possessed for their age

So it is a normal and idiomatic sentence, not a word-for-word translation from English.