Лучше заранее приготовить тёплую воду и чистое полотенце, если потом придётся мыть бутылочку.

In Russian, лучше often works as an impersonal word meaning it’s better to... or you’d better.... It does not always need an explicit comparison.

So:

• Лучше заранее приготовить... = It’s better to prepare ... in advance
• more literally: Better to prepare ... in advance

Russian often leaves out the English-style it is in this kind of sentence.

You could think of it as a general piece of advice rather than a strict comparison.

Because лучше is followed here by an infinitive to express what action is advisable.

Pattern:

• Лучше + infinitive
• Лучше сделать это сейчас. = It’s better to do it now.
• Лучше подождать. = It’s better to wait.

So:

• Лучше заранее приготовить... = It’s better to prepare ... in advance

This is a very common Russian structure.

Приготовить is the perfective form, while готовить is imperfective.

Here, the speaker means prepare it ahead of time as a completed action. That fits the perfective verb:

• приготовить = to prepare, get ready, make ready (completed result)
• готовить = to be preparing / to prepare in general / repeatedly

Since the sentence is about doing this one practical action in advance, приготовить is the natural choice.

Compare:

• Лучше заранее приготовить воду.
  = better to get the water ready beforehand

• Я обычно готовлю воду заранее.
  = I usually prepare the water beforehand

The second one is about a habit, so imperfective makes more sense there.

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

So:

• Лучше заранее приготовить...
  = It’s better to prepare ... in advance

It emphasizes that you do this before the need actually arises.

Common examples:

• Спасибо заранее. = Thanks in advance.
• Надо всё узнать заранее. = You need to find everything out beforehand.

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

1. тёплую воду

• вода is feminine
• accusative singular of вода is воду
• adjective тёплая becomes тёплую to match it

So:

• nominative: тёплая вода
• accusative: тёплую воду

2. чистое полотенце

• полотенце is neuter
• for inanimate neuter nouns, nominative and accusative are the same
• adjective also stays the same form

So:

• nominative: чистое полотенце
• accusative: чистое полотенце

That is why the two object phrases look different: the nouns have different genders and different accusative endings.

Russian does not have articles like a, an, and the.

So:

• тёплую воду can mean warm water
• чистое полотенце can mean a clean towel or the clean towel, depending on context

The exact sense comes from the situation, not from an article.

In this sentence, English would naturally say warm water and a clean towel, but Russian simply says:

• тёплую воду и чистое полотенце

Придётся is the future form of прийтись, a verb that often means to have to, to be forced to, or to end up needing to.

In this sentence:

• если потом придётся мыть бутылочку
  = if later you have to wash the bottle

A very literal idea is something like: if it falls to one to wash the bottle later.

This verb is common in impersonal expressions:

• Мне придётся уйти. = I’ll have to leave.
• Нам придётся подождать. = We’ll have to wait.

In your sentence, there is no explicit person like мне or вам, so it stays general: if it becomes necessary later to wash the bottle.

After придётся, Russian often uses an infinitive to describe the required action. Here мыть is imperfective.

That sounds natural because the sentence focuses on the situation of having to wash the bottle, not strongly on the completed result.

• мыть = to wash, be washing
• помыть = to wash completely / wash once to completion

In many contexts, both can be possible, but the nuance changes a bit:

• придётся мыть бутылочку = you’ll have to wash the bottle
• придётся помыть бутылочку = you’ll have to wash the bottle (and get it washed / complete the task)

The imperfective is very common after words expressing necessity, especially when the action is viewed more generally.

Бутылочку is the accusative singular of бутылочка, which is a diminutive form of бутылка.

So:

• бутылка = bottle
• бутылочка = little bottle / bottle (in a softer, more familiar, more affectionate way)

In many real-life contexts, бутылочка often refers to a baby bottle.

That is probably the intended meaning here, especially because the sentence mentions warm water and a towel, which sounds like caregiving.

Case-wise:

• nominative: бутылочка
• accusative: бутылочку

Because it is feminine and inanimate, the accusative singular ends in -у / -ю.

So the form is not random; it is just the normal accusative of the diminutive noun.

Not always, but very often in everyday speech it can mean that, especially in the right context.

Literally, it is just a diminutive of бутылка, so depending on context it could mean:

• a small bottle
• a bottle spoken of affectionately or casually
• a baby bottle

Here, because of мыть бутылочку and the general domestic context, many learners would naturally understand it as baby bottle.

So context matters a lot.

Yes. Если is the ordinary word for if.

So:

• если потом придётся мыть бутылочку
  = if later it becomes necessary to wash the bottle

The whole sentence means something like:

• It’s better to prepare warm water and a clean towel in advance if you’ll have to wash the bottle later.

This is a normal conditional clause.

Потом means later, afterwards, or then.

In this sentence:

• если потом придётся мыть бутылочку
  = if later you have to wash the bottle

It contrasts with заранее:

• заранее = beforehand
• потом = later

So the sentence has a nice time contrast:

• prepare things beforehand
• in case later you need them

Its position is natural because Russian word order is flexible, and потом is placed near the idea of придётся мыть to show when that need may arise.

Yes, Russian word order is flexible, though some orders sound more natural than others.

Original:

• Лучше заранее приготовить тёплую воду и чистое полотенце, если потом придётся мыть бутылочку.

You could also say:

• Если потом придётся мыть бутылочку, лучше заранее приготовить тёплую воду и чистое полотенце.

This puts the condition first:

• If you’ll have to wash the bottle later, it’s better to prepare warm water and a clean towel in advance.

The meaning stays basically the same. The difference is mainly in emphasis and information flow.

It is neutral everyday Russian.

A few points:

• лучше
  • infinitive is common in both speech and writing
• заранее, приготовить, придётся are all normal standard words
• бутылочка adds a slightly softer, more domestic tone because it is a diminutive

So the sentence sounds natural in practical advice, especially in a family or caregiving context.

Yes. Russian often omits it when the advice is general, but you can add it if needed.

For example:

• Вам лучше заранее приготовить тёплую воду и чистое полотенце...
  = You’d better prepare warm water and a clean towel in advance... (formal/plural)

• Тебе лучше заранее приготовить тёплую воду и чистое полотенце...
  = You’d better prepare warm water and a clean towel in advance... (informal singular)

Without вам / тебе, the sentence sounds more general and impersonal: simply it’s better to...

Yes, мыть бутылочку is perfectly normal.

It simply means to wash the bottle or, in context, to wash the baby bottle.

Depending on the context, speakers could also use related verbs, for example:

• помыть бутылочку = wash the bottle completely
• сполоснуть бутылочку = rinse the bottle
• простерилизовать бутылочку = sterilize the bottle

But мыть бутылочку is a straightforward, natural phrase.

A useful way to break it down is:

• Лучше = it’s better
• заранее приготовить = to prepare in advance
• тёплую воду и чистое полотенце = warm water and a clean towel
• если потом придётся = if later it becomes necessary / if later you’ll have to
• мыть бутылочку = wash the bottle

So the structure is:

• Лучше + infinitive + objects, если + clause

More abstractly:

• It’s better to do X in advance, if later you may have to do Y.

This is a very useful Russian sentence pattern for giving practical advice.