Мне не нужен такой подарок.

Because Russian expresses this idea differently from English.

In English, we say I don’t need this kind of gift, with I as the subject.

In Russian, the structure is closer to:

To me, such a gift is not needed.

So:

• мне = to me (dative case)
• подарок = the thing that is or is not needed

That is why мне is used instead of я.

Нужен means needed or necessary.

It comes from нужный (necessary / needed), but here it appears in the short form, which is very common in sentences like this.

So Мне не нужен такой подарок literally means:

Such a gift is not needed to me.

In natural English, that becomes:

I don’t need such a gift or I don’t want a gift like that (depending on context).

Because нужен agrees with подарок, and подарок is:

• masculine
• singular

So the short-form adjective must also be masculine singular:

• masculine: нужен
• feminine: нужна
• neuter: нужно
• plural: нужны

Examples:

• Мне не нужна эта книга. = I don’t need this book.
• Мне не нужно это письмо. = I don’t need this letter.
• Мне не нужны эти вещи. = I don’t need these things.

Because in this construction, подарок is the grammatical subject of the sentence.

The pattern is:

[person in dative] + [не нужен / нужна / нужно / нужны] + [thing in nominative]

So:

• мне = to me
• не нужен = is not needed
• такой подарок = such a gift

Even though English uses I as the subject, Russian treats the gift as the thing being described: it is not needed.

That is a very reasonable question, because Russian sometimes uses the genitive after negation.

But here, подарок is not the direct object of a verb like have or see. It is the subject-like noun in the construction with нужен. Because of that, the nominative is normal:

• Мне не нужен такой подарок.

So even with не, you usually keep the nominative here.

Такой means such, this kind of, or that kind of, depending on context.

So такой подарок can mean:

• such a gift
• a gift like that
• this sort of gift

It often points to the type or quality of the gift, not just the fact that it is a gift.

Yes. Russian word order is flexible, and changing it can shift the emphasis.

For example:

• Мне не нужен такой подарок.
  Neutral: I don’t need such a gift.

• Такой подарок мне не нужен.
  Stronger focus on this kind of gift: A gift like this is not something I need.

• Мне такой подарок не нужен.
  Also very natural; slightly emphasizes такой подарок within the sentence.

All of these are grammatical. The basic meaning stays the same, but the emphasis changes.

Not exactly.

• Мне не нужен такой подарок = I don’t need such a gift.
• Я не хочу такой подарок = I don’t want such a gift.

The first one sounds more like it is unnecessary for me.
The second one is a more direct statement of wanting / not wanting.

Also, with хотеть, Russian more naturally says:

• Я не хочу такой подарок
• or often Я не хочу такого подарка in some contexts

But не нужен is a very common and natural way to express lack of need.

It can sound blunt, depending on tone and context.

By itself, Мне не нужен такой подарок is a straightforward statement: I don’t need this kind of gift. If you say it sharply, it may sound ungrateful or dismissive.

To make it softer, Russian speakers often add polite words or rephrase it, for example:

• Спасибо, но мне такой подарок не нужен. = Thank you, but I don’t need this kind of gift.
• Спасибо, но это не совсем то, что мне нужно. = Thank you, but it’s not exactly what I need.

So the sentence itself is not inherently rude, but it can sound strong if used without softening.

Yes. A very literal breakdown is:

• Мне = to me
• не = not
• нужен = needed
• такой подарок = such a gift / a gift like that

So the sentence is literally:

To me, such a gift is not needed.

That literal structure helps explain the grammar:

• the person is in the dative
• the thing needed is in the nominative
• нужен agrees with the thing, not the person

The normal stress is:

• мне
• не
• ну́жен
• тако́й
• пода́рок

So the sentence is pronounced:

Мне не ну́жен тако́й пода́рок.

The stressed syllables are:

• ну́-
• -ко́й
• да́-

This is useful because stress in Russian is unpredictable and must often be learned with each word.