Для шашлыка лучше замариновать мясо заранее.

Для шашлыка means for shashlik / for a barbecue meat dish.

The preposition для almost always requires the genitive case, so:

• шашлык = shashlik
• для шашлыка = for shashlik

In this sentence, для шашлыка gives the purpose or context: when making shashlik or for shashlik.

So the sentence is not talking about meat in general, but specifically about meat intended for this dish.

Russian often leaves out the subject when the meaning is general or obvious from context.

Here, лучше замариновать мясо заранее literally means something like:

• It is better to marinate the meat in advance
• You should marinate the meat in advance
• It’s best to marinate the meat ahead of time

English usually wants some kind of subject, even if it is just it, but Russian can simply use лучше + infinitive to express general advice.

Лучше + infinitive is a very common Russian pattern for giving advice or saying what is preferable.

So:

• лучше замариновать = it is better to marinate
• лучше подождать = it is better to wait
• лучше сделать это сейчас = it is better to do it now

This structure is impersonal. It does not directly say who should do the action, but usually means one should, you should, or it’s best to.

This is about aspect.

• мариновать = imperfective, focusing on the process or repeated action
• замариновать = perfective, focusing on completing the action

In this sentence, the idea is to get the meat marinated before the right moment. That is a completed result, so замариновать fits well.

Compare:

• Лучше замариновать мясо заранее.
  = It’s better to marinate the meat in advance.
  (focus on doing it successfully beforehand)

• Нужно мариновать мясо несколько часов.
  = You need to marinate the meat for several hours.
  (focus on the process/duration)

So the perfective verb is natural here because the advice is about completing the preparation ahead of time.

Заранее means in advance, ahead of time, or beforehand.

In this sentence, it tells us that the meat should be marinated before the actual cooking time.

Examples:

• Подготовь всё заранее. = Prepare everything in advance.
• Я купил билеты заранее. = I bought the tickets ahead of time.

So заранее is an adverb describing when the marinating should happen.

Yes, мясо is the direct object of замариновать, so it is in the accusative case.

However, мясо is a neuter inanimate noun, and for many neuter inanimate nouns, the nominative and accusative forms are the same.

So:

• nominative: мясо
• accusative: мясо

That is why the form does not visibly change.

Шашлык is a specific dish: pieces of meat, usually marinated and cooked on skewers over fire or coals.

It is related to the general idea of barbecue, but it is not exactly the same as the English word barbecue, which can mean:

• a cooking method
• an outdoor meal/event
• the grill itself
• the food

Шашлык is more specific: it usually refers to the meat dish itself.

So Для шашлыка is more literally for shashlik, though in natural English the meaning may be given as for barbecue depending on context.

Yes. Russian word order is flexible, though different orders can change emphasis.

The neutral order here is:

• Для шашлыка лучше замариновать мясо заранее.

You might also hear:

• Мясо для шашлыка лучше замариновать заранее.
• Лучше заранее замариновать мясо для шашлыка.

These all mean roughly the same thing, but the focus shifts slightly:

• Для шашлыка... puts the dish/context first
• Мясо... puts the meat first
• Лучше заранее... emphasizes the recommendation and timing

So the original sentence is natural, but not the only possible wording.

You could say it, but it sounds less natural in this context.

мариновать (imperfective) emphasizes the process, while замариновать (perfective) emphasizes completing the preparation. Since the point is practical advice—make sure the meat is already marinated beforehand—the perfective замариновать is better.

Using мариновать might sound more like a general habit or process statement, while замариновать sounds like a concrete recommendation for a particular preparation.

So the original sentence is the more idiomatic choice.

It is basically neutral and natural everyday Russian.

It would work in:

• casual conversation
• a recipe
• cooking advice
• an article or blog post

It is not especially formal, but it is not slangy either. It is a standard, useful sentence pattern.

A fairly literal translation would be:

• For shashlik, it is better to marinate the meat in advance.

More natural English versions might be:

• For shashlik, it’s best to marinate the meat ahead of time.
• If you’re making shashlik, it’s better to marinate the meat beforehand.
• For barbecue, it’s best to marinate the meat in advance.

The exact English wording can vary, but the Russian structure is very compact and natural.