Если хотите, я принесу Вам салат, в который я уже добавил фасоль и кукурузу.

Хотите is the 2nd person plural form of хотеть. In Russian, that form is used for:

• more than one person: if you all want
• one person politely/formally: if you want

So this sentence is either addressing several people or one person in a polite way. If you were speaking informally to one friend, you would say Если хочешь.

Because this is a real, open condition, not a hypothetical one.

• Если хотите = if you want
• Если бы хотели = if you wanted / if you were to want, which sounds more hypothetical or less direct

Here the speaker is making a normal offer in the present situation, so если without бы is the natural choice.

Принесу is the perfective future of принести. It means a single completed action: I will bring.

That fits this situation well, because the speaker means one specific act of bringing the salad.

• принесу = I’ll bring it over / I’ll bring it once
• буду приносить = I will be bringing / I will bring repeatedly, which does not fit as well here

Russian often uses the perfective future for this kind of practical promise or offer.

It is in the form Вам because принести takes the dative for the person who receives something:

• принести кому? — to bring to whom?
• Вам = to you

The capitalization is a matter of polite writing style. In letters, messages, or formal communication, Russians sometimes write Вы, Вас, Вам with a capital letter to show respect.

So:

• Вам = polite/respectful spelling
• вам = also correct, and very common in modern writing

Салат is the direct object of принесу, so it is in the accusative case. But for many masculine inanimate nouns, the accusative singular is the same as the nominative singular.

So:

• nominative: салат
• accusative: салат

That is why the form does not change.

Also, Russian has no articles, so салат can mean a salad or the salad, depending on context.

This is one of the most important grammar points in the sentence.

The relative pronoun который must match the role of салат inside the relative clause. If we rewrite the clause without который, we get:

Я уже добавил фасоль и кукурузу в салат.

Here, салат appears after в and is in the accusative, because with добавить the idea is to add something into something.

So when салат becomes a relative pronoun, it keeps that same structure:

• в салат → в который

Why not в котором?

• в котором would be in which with the prepositional case, usually used for location or state
• but добавить normally points to the target of adding, so Russian uses в + accusative here

So even though English might say the salad in which I already added..., Russian naturally says в который because of the verb pattern.

It actually is in the accusative here, but for masculine inanimate singular, the accusative form of который looks the same as the nominative:

• nominative masculine inanimate: который
• accusative masculine inanimate: который

So the case change is there grammatically, but it is not visible in the ending.

Добавил is perfective past, and it emphasizes a completed result: the beans and corn have already been added.

That works well with уже:

• уже добавил = has already added / already added

If you used добавлял, that would be imperfective past, which usually focuses more on the process, repetition, or background action:

• добавлял = was adding / used to add / added at some point, with less focus on the completed result

Here the speaker wants to say the salad is already prepared in that way, so добавил is the natural choice.

Yes. In the past tense, Russian verbs agree with the subject in gender and number.

• добавил = masculine singular
• добавила = feminine singular
• добавило = neuter singular
• добавили = plural

So я уже добавил suggests that the speaker is male. If the speaker were female, it would be я уже добавила.

They are the direct objects of добавил, so they are in the accusative case.

• фасоль is a feminine noun ending in -ь, and in the singular its nominative and accusative are the same: фасоль
• кукуруза is a feminine noun ending in -а, so the accusative singular changes to -у: кукурузу

So:

• добавил фасоль
• добавил кукурузу

are exactly what you would expect.

That is a very natural position for уже. It usually goes near the verb it modifies.

• я уже добавил = I have already added

Russian word order is flexible, but this order sounds neutral and natural. Moving words around can change emphasis:

• я уже добавил фасоль и кукурузу = neutral
• я фасоль и кукурузу уже добавил = stronger emphasis on what was added
• уже добавил я... = marked or poetic/emphatic

So the sentence uses the most ordinary, straightforward order.

There are two commas for two different reasons.

First comma: Если хотите, ...

This separates the introductory conditional clause если хотите from the main clause. In English, this is similar to If you want, ...

Second comma: ..., в который я уже добавил ...

This comma introduces a relative clause, the part that describes салат.

So the structure is:

• Если хотите = introductory conditional clause
• я принесу Вам салат = main clause
• в который я уже добавил фасоль и кукурузу = relative clause describing the salad

Yes, it often could be.

Russian frequently omits personal pronouns when the meaning is clear from the verb form. So this would also be possible:

Если хотите, я принесу Вам салат, в который уже добавил фасоль и кукурузу.

That still clearly means I already added beans and corn to it, because добавил is first-person singular only through context? Actually the verb form itself is just masculine past, so the subject is understood from the surrounding sentence and context.

Including я makes the clause a bit more explicit and can slightly emphasize the speaker’s own action.