Для супа мне не нужен блендер, а вот для соуса блендер очень удобен.

Because they follow the preposition для, which normally requires the genitive case.

• для супа = for soup
• для соуса = for sauce

The dictionary forms are:

• суп
• соус

After для, they become:

• супа
• соуса

So this is a very common pattern: для + genitive.

Yes. Для usually means for. In this sentence, для супа and для соуса mean something like:

• for making soup
• for making sauce
• when it comes to soup / sauce

Russian often uses для + genitive in cases where English might use a slightly looser phrasing. So Для супа мне не нужен блендер is not just about the soup as an object; it means for soup, I don’t need a blender.

Мне is in the dative case and means to me / for me. In this construction, Russian often expresses the idea as:

• to me, a blender is not needed
• more natural English: I don’t need a blender

So grammatically, блендер is the thing being talked about, and мне shows who needs or does not need it.

This pattern is very common in Russian:

• Мне нужен кофе. = I need coffee.
• Мне не нужна машина. = I don’t need a car.
• Мне нужны деньги. = I need money.

Because нужен agrees with блендер, which is:

• masculine
• singular

So the forms are:

• нужен — masculine singular
• нужна — feminine singular
• нужно — neuter singular
• нужны — plural

Examples:

• Мне нужен блендер.
• Мне нужна ложка.
• Мне нужно полотенце.
• Мне нужны тарелки.

So here не нужен matches блендер.

Yes, in this sentence нужен expresses the idea of being needed.

Literally, Мне не нужен блендер is closer to:

• A blender is not needed for me

But in natural English, we say:

• I don’t need a blender

So Russian uses a structure that is slightly different from English, but the meaning is the same.

Not in the same way.

You can say:

• Мне не нужен блендер. = I don’t need a blender.

But нужно is more impersonal and often works with infinitives or whole actions:

• Мне нужно купить блендер. = I need to buy a blender.
• Для супа не нужно использовать блендер. = For soup, it isn’t necessary to use a blender.

So:

• нужен = agrees with a noun
• нужно = often means it is necessary or is used in impersonal structures

А often means but, while, or and as for depending on context.
Вот adds emphasis or contrast.

Together, а вот often means something like:

• but
• whereas
• but when it comes to...
• now, as for...

In this sentence:

• Для супа мне не нужен блендер, а вот для соуса блендер очень удобен.

The speaker is making a contrast:

• For soup, I don’t need a blender
• but for sauce, a blender is very convenient

So а вот highlights the second, contrasting idea.

Russian often repeats nouns where English might prefer a pronoun. Repeating блендер here makes the contrast clear and sounds natural.

The sentence compares two situations:

• for soup — blender not needed
• for sauce — blender very convenient

If you replaced it with a pronoun, it might sound less clear or less natural depending on context. Repetition in Russian is often more acceptable than in English.

Удобен is the short form of the adjective удобный.

In Russian, short-form adjectives are often used:

• in the predicate
• to describe a temporary, practical, or evaluative quality
• after an implied is

So:

• Блендер очень удобен. = A blender is very convenient.

This sounds natural because the adjective is part of the main statement.

Compare:

• удобный блендер = a convenient blender
  
  • full form, used before a noun
• блендер удобен = the blender is convenient
  
  • short form, used as the predicate

Yes, you could, and native speakers do say that in conversation. But there is a nuance.

• Блендер очень удобен sounds a bit more standard, compact, and bookish or formal.
• Блендер очень удобный sounds more conversational and descriptive.

In this sentence, удобен fits very well because the speaker is making a practical judgment: the blender is convenient/useful for sauce.

Because in the present tense, Russian usually omits the verb to be.

So:

• блендер очень удобен

literally looks like:

• blender very convenient

but it means:

• the blender is very convenient

This is completely normal in Russian.

Compare:

• Он врач. = He is a doctor.
• Суп вкусный. = The soup is tasty.
• Блендер удобен. = The blender is convenient.

The word order is flexible, but the original order sounds natural because it highlights the contrast clearly.

Original:

• Для супа мне не нужен блендер, а вот для соуса блендер очень удобен.

This structure puts the two uses side by side:

• for soup
• for sauce

You could rearrange parts of it, but the emphasis would change. For example:

• Мне не нужен блендер для супа, а для соуса он очень удобен.

This is also possible, but it feels slightly different in focus. The original version foregrounds the contrast between суп and соус more strongly.

Because а is a coordinating conjunction connecting two clauses, and in Russian that normally takes a comma.

Here the two parts are:

• Для супа мне не нужен блендер
• а вот для соуса блендер очень удобен

The comma marks the contrast between them.

No. Here удобен means convenient, handy, or useful in practice.

The adjective удобный / удобен can sometimes mean comfortable, but the exact meaning depends on context.

For example:

• удобный стул = a comfortable chair
• удобный инструмент = a handy / convenient tool
• блендер очень удобен = a blender is very convenient

So in this sentence, it is clearly about practical usefulness, not physical comfort.