На выходных в парке много людей: кто-то идёт по велодорожке, а кто-то отдыхает на лавочке под дубом.

На выходных means at the weekend / on the weekend / over the weekend, depending on context.

Russian often uses выходные as a plural noun meaning days off / the weekend. That is why you see a plural form here. In this expression, на выходных is a very common conversational way to say during the weekend.

A slightly more neutral or textbook-style version is в выходные. Both are common, but на выходных sounds very natural in everyday speech.

Because в here means in and shows location, Russian uses the prepositional case after в for location.

So:

• парк = park
• в парке = in the park

This is a very common pattern:

• в доме = in the house
• в городе = in the city
• в парке = in the park

If there were movement into the park, Russian would usually use the accusative instead: в парк.

Russian often leaves out the verb to be in the present tense.

So в парке много людей literally looks like in the park many people, but it means there are many people in the park.

This is completely normal in Russian. Compare:

• Здесь много машин. = There are many cars here.
• В комнате тихо. = The room is quiet / It is quiet in the room.

So the idea of there are is understood without saying an actual verb.

After words like много, Russian normally uses the genitive case.

That is why:

• люди = people
• людей = of people / people in the genitive plural

So:

• много людей = many people

This happens with other quantity words too:

• мало времени = little time
• несколько книг = several books
• пять студентов = five students

For an English speaker, it helps to remember that Russian quantity expressions often trigger a different case.

Yes. The basic plural form is люди meaning people, and the genitive plural is людей.

This word is a bit irregular because the singular is usually человек, while the plural is люди. So the forms do not look as neatly related as many other nouns.

A very useful mini-set to remember is:

• человек = person
• люди = people
• людей = of people / people after quantity words like много

This structure means something like some people ... while others ...

Literally, кто-то means someone, but when repeated in this kind of sentence, it divides a group into different unspecified people:

• кто-то идёт... = some are walking...
• а кто-то отдыхает... = and others are resting...

It is a very natural Russian way to describe different members of a crowd doing different things.

Because кто-то is grammatically singular.

Even though in English we may translate the overall idea as some people and others, each кто-то itself means someone, so Russian uses a singular verb:

• кто-то идёт
• кто-то отдыхает

This is grammar following the form, not the broader real-world meaning.

This is about Russian verbs of motion.

• идти → идёт = to be going, to be walking in one direction, right now
• ходить = to go/walk around, to go habitually, to go there and back, or in a non-directional way

Here the sentence describes what is happening in the scene at this moment, and the person is moving along the bike path in a specific direction, so идёт is the natural choice.

If you said ходит, it would suggest something more habitual or less direction-focused.

After по in the sense of movement along / on / via, Russian usually uses the dative case.

So:

• велодорожка = bike path / cycle path
• по велодорожке = along the bike path

This is a common pattern:

• идти по улице = walk along the street
• ехать по дороге = drive along the road
• гулять по парку = walk around the park

So велодорожке is the dative singular form.

Велодорожка is a compound noun meaning bike lane, cycle path, or bicycle path.

It is made from:

• вело- = bicycle-related
• дорожка = little road, path, track

So по велодорожке means the person is walking along the bike path. In real life that may or may not be ideal behavior, but grammatically that is what the sentence says.

Here а marks a contrast or comparison between two parts of the scene.

So:

• кто-то идёт по велодорожке, а кто-то отдыхает...

means something like:

• some are walking along the bike path, while others are resting...

If you used и, it would sound more like simple addition. А is better because it sets one group against another in a gentle contrast.

Because на with a location meaning on uses the prepositional case.

So:

• лавочка = bench
• на лавочке = on the bench

This tells us where the person is resting. Compare:

• сидеть на стуле = sit on a chair
• лежать на диване = lie on the sofa
• отдыхать на лавочке = rest on a bench

If there were movement onto the bench, Russian would normally use the accusative: на лавочку.

The difference is location versus direction/movement.

• на лавочке = on the bench, located there
• на лавочку = onto the bench, moving to it

So in this sentence, отдыхает на лавочке means the person is already there, resting on the bench.

Compare:

• Он сел на лавочку. = He sat down onto the bench.
• Он сидит на лавочке. = He is sitting on the bench.

Дубом is the instrumental singular of дуб meaning oak tree.

After под:

• with location you usually get the instrumental
• with motion toward a position under something you usually get the accusative

So:

• под дубом = under the oak tree
• под дуб = to under the oak tree

In this sentence, the person is resting there, so it is location, not motion: под дубом.

The first part gives a general statement:

• На выходных в парке много людей

Then the part after the colon gives examples or a breakdown of what those people are doing:

• кто-то идёт...
• а кто-то отдыхает...

So the colon works like namely / for example / as follows. It introduces an explanation or illustration of the previous statement.

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

For example, this sentence could be rearranged in several ways and still be understandable. But the original order sounds natural because it moves from:

1. time: На выходных
2. place: в парке
3. general scene: много людей
4. details: what different people are doing

That makes it flow very naturally as a description.

Отдыхать means to rest, to relax, or sometimes simply to spend time leisurely.

In this sentence, отдыхает на лавочке под дубом suggests someone is sitting or taking it easy on the bench under the oak tree. It does not necessarily mean they are exhausted and recovering. It is often used more broadly than English rest.

So depending on context, it can feel like:

• resting
• relaxing
• taking a break
• chilling out

Yes, it sounds natural and descriptive.

It paints a scene in a very typical Russian way: first giving the setting, then showing different people doing different things. Expressions like На выходных, много людей, and кто-то ... а кто-то ... are all common and idiomatic.

The only small real-world note is that идёт по велодорожке literally means someone is walking along a bike path, which is grammatically fine even if, in some parks, that might be a place meant more for bicycles.