Пока малышка ползает по комнате, мама ставит манеж ближе к окну.

Here пока means while.

So the sentence means that one action is happening at the same time as another:

• Пока малышка ползает по комнате, мама ставит манеж...
• While the little girl is crawling around the room, Mom is moving/placing the playpen...

Пока can also mean until in other sentences, so learners often get confused. The meaning depends on context.

Compare:

• Подожди, пока мама придёт. = Wait until Mom comes.
• Пока мама готовит, дети играют. = While Mom is cooking, the children are playing.

Here it is clearly the while meaning.

Because the sentence has two clauses:

1. Пока малышка ползает по комнате
2. мама ставит манеж ближе к окну

The first clause begins with пока, and in Russian a subordinate clause like that is normally separated by a comma.

So:

• Пока малышка ползает по комнате, мама ставит манеж ближе к окну.

If you reversed the order, you would still use a comma:

• Мама ставит манеж ближе к окну, пока малышка ползает по комнате.

Малышка literally means something like little one, little girl, or baby girl, depending on context.

It is an affectionate word. It sounds warmer and more personal than a neutral word like:

• ребёнок = child
• девочка = girl

So малышка suggests a very young child and often carries a loving tone.

Ползает is from ползать, meaning to crawl.

In this sentence it is:

• 3rd person singular
• present tense
• imperfective aspect

So малышка ползает means the little girl is crawling / crawls around.

The imperfective is used because the action is ongoing, repeated, or viewed as a process. That fits well with пока:

• the child is in the middle of crawling around
• meanwhile, the mother is doing something else

Both are possible in Russian, but they mean slightly different things.

• в комнате = in the room
• по комнате = around the room / about the room

So:

• ползает в комнате = crawls in the room
• ползает по комнате = crawls around the room

Here по комнате is better because it emphasizes movement around within the room, not just location.

After по, Russian often uses the dative case when talking about movement around an area.

So:

• комната = nominative
• по комнате = dative

That is why you get комнате.

This is a very common pattern:

• ходить по парку = to walk around the park
• бегать по двору = to run around the yard
• ползать по комнате = to crawl around the room

This is an aspect question.

• ставит = imperfective
• поставит = perfective

Here ставит is used because the sentence describes the action as ongoing or in progress at the same time as the baby’s crawling.

So:

• мама ставит манеж... = Mom is placing / moving the playpen...
• мама поставит манеж... = Mom will place the playpen / will finish placing it

Because the sentence focuses on what is happening while something else is happening, the imperfective ставит is natural.

Russian does not have a separate tense form exactly like the English present continuous.

Instead, Russian usually uses the present tense of an imperfective verb to express both:

• a general present action
• an action happening right now

So:

• ползает can mean crawls or is crawling
• ставит can mean puts/places or is putting/placing

The context tells you which English translation sounds best.

Here манеж means playpen.

It can also mean an arena or riding hall in other contexts, but with a baby and a room, it clearly means a child’s playpen.

So in this sentence:

• мама ставит манеж ближе к окну
• Mom is moving the playpen closer to the window

Ближе means closer.

It is the comparative form of близко = near / close.

So:

• близко = close
• ближе = closer

Russian often uses this kind of comparative without a word for than if the comparison target is obvious from the phrase that follows:

• ближе к окну = closer to the window

The preposition к takes the dative case and means to or toward.

So:

• окно = window
• к окну = toward the window / to the window

That is why the form is окну.

In this sentence:

• ближе к окну = closer to the window

A few similar examples:

• к двери = to the door
• к стене = to the wall
• к маме = to Mom

It can be translated several ways depending on context.

The basic meaning of ставить is to put/set something in an upright or intended position. In this sentence, because the playpen is being repositioned, English might naturally say:

• puts the playpen closer to the window
• places the playpen closer to the window
• moves the playpen closer to the window

All of those can work.

So the Russian is not necessarily emphasizing whether she is placing it for the first time or just shifting it a bit. It simply says she is setting it closer to the window.

Yes. Russian word order is more flexible than English word order.

This sentence is neutral and natural:

• Пока малышка ползает по комнате, мама ставит манеж ближе к окну.

But you could also say:

• Мама ставит манеж ближе к окну, пока малышка ползает по комнате.

That still means essentially the same thing.

Changing word order in Russian often affects emphasis more than basic meaning. The original version puts the while the baby is crawling part first, setting the scene before the main action.

Russian does not have articles.

So nouns like:

• малышка
• комната
• мама
• манеж
• окно

do not use words corresponding to a or the.

Whether English should say a playpen or the playpen, a room or the room, depends on context and translation. Russian leaves that unstated.

So learners should not try to look for a hidden article in the Russian sentence; there simply isn’t one.