Давай разделим яблоки поровну.

Here давай means let’s ... in a conversational way.

It comes from the verb давать (to give), but in this pattern it does not literally mean give. In everyday Russian, давай is often used to suggest doing something together:

• Давай пойдём. — Let’s go.
• Давай посмотрим. — Let’s see.
• Давай разделим яблоки поровну. — Let’s divide the apples equally.

It sounds natural and common in speech.

Разделим is the 1st person plural future form of разделить.

So literally, it is something like we will divide. But after давай, this future form is commonly used to make a suggestion:

• Давай разделим... — Let’s divide...

So grammatically it is a future form, but functionally in this sentence it works like let’s.

Разделить is a perfective verb, and that fits the meaning well because the sentence is about a single completed action: dividing the apples into equal parts.

Russian often uses:

• perfective for a completed result
• imperfective for process, repetition, or general activity

Here the focus is on the result: the apples end up divided.

Compare:

• Давай разделим яблоки поровну. — Let’s divide the apples equally.
  → one completed action
• Мы делим яблоки поровну. — We are dividing / divide the apples equally.
  → process or general action

Russian usually does not need a subject pronoun if the verb already shows who is doing the action.

In разделим, the ending -им shows we. So мы is unnecessary unless you want emphasis.

• Давай разделим яблоки поровну. — normal, neutral
• Давай мы разделим яблоки поровну. — more emphatic, like let’s us divide the apples equally

English needs we in let’s, but Russian often leaves it out.

Яблоки is the accusative plural form of яблоко (apple), because it is the direct object of разделим.

The tricky part is that with inanimate nouns, the accusative plural looks the same as the nominative plural.

So:

• singular: яблоко
• plural nominative: яблоки
• plural accusative: яблоки

That is why the form is яблоки here.

Поровну means equally, into equal shares, or evenly.

It is an adverb, so it does not change form.

It is often used with verbs of dividing or sharing:

• разделить поровну — to divide equally
• поделить поровну — to split equally
• всем поровну — an equal amount for everyone

In this sentence, поровну tells us how the apples should be divided.

Yes, Давай поделим яблоки поровну is also very natural.

Both разделить and поделить can mean to divide / split up. In many everyday contexts, they are very close in meaning.

A rough tendency:

• разделить can sound a bit more like divide into parts
• поделить often sounds like share/split up

But in this sentence, either verb would be normal.

Yes. Russian word order is flexible, although the original order is neutral and natural:

• Давай разделим яблоки поровну.

Other orders are possible, but they change emphasis slightly:

• Давай яблоки разделим поровну.
  → extra focus on the apples
• Давай разделим поровну яблоки.
  → possible, but less neutral
• Яблоки давай разделим поровну.
  → sounds like introducing the topic as for the apples...

So the original version is probably the best default choice for learners.

Use давайте instead of давай:

• Давайте разделим яблоки поровну.

Давайте is used:

• when speaking politely to one person
• when speaking to a group

So:

• давай = informal singular
• давайте = polite singular or plural

This is one of the most useful informal/formal contrasts in Russian.

The stress is:

• давАй
• разделИм
• Яблоки
• порОвну

So a simple pronunciation guide is:

dav-AY raz-de-LEEM YA-bla-ki pa-ROV-nu

A few notes:

• In яблоки, the first syllable is stressed: Яблоки
• Unstressed о is reduced in pronunciation, so it often sounds closer to a in fast speech
• Давай разделим яблоки поровну is said smoothly as one suggestion, with the main sentence stress often falling on поровну or яблоки, depending on emphasis

Usually, the natural version is давай разделим яблоки поровну.

Russian most commonly uses давай / давайте with:

• a 1st person plural verb form:
  Давай разделим
• or sometimes an infinitive in certain conversational patterns:
  Давай смотреть, давай думать

But with this sentence, давай разделить sounds less natural than давай разделим.

So for a learner, the safest choice is:

• Давай разделим яблоки поровну.