По выходным я люблю вставать поздно.

По выходным is a very common Russian way to say on weekends in the sense of a repeated habit.

The pattern is:

по + dative plural = on / during / every when talking about recurring times

Similar examples:

• по утрам = in the mornings
• по вечерам = in the evenings
• по субботам = on Saturdays

So По выходным я люблю вставать поздно means that this is something the speaker generally likes to do on weekends, not just once.

Because after по in this kind of time expression, Russian uses the dative plural.

The base form is выходные (weekend days / days off), but after по it changes to выходным.

So:

• выходные = weekends / days off
• по выходным = on weekends

This is a grammar pattern, not a random form.

Originally, выходной is an adjective meaning something like day-off or non-working. But in real Russian, выходные is very often used like a noun meaning the weekend or days off.

So in this sentence, it functions like a noun:

• выходные = the weekend / weekends
• по выходным = on weekends

Russian does this a lot: adjectives can become noun-like when the missing noun is understood.

Because вставать is imperfective, and imperfective is normally used for:

• repeated actions
• habits
• general preferences

Here the speaker is talking about a habit or usual preference: they like getting up late on weekends.

So:

• вставать = to get up, habitually / in general
• встать = to get up once, as a completed action

After люблю when you mean I like doing X in general, Russian usually uses the imperfective:

• Я люблю читать. = I like reading.
• Я люблю гулять. = I like walking.
• Я люблю вставать поздно. = I like getting up late.

Because Russian commonly uses:

любить + infinitive

to mean to like/love doing something.

So:

• люблю читать = I like reading
• люблю готовить = I like cooking
• люблю вставать поздно = I like getting up late

English often uses -ing after like, but Russian uses the infinitive instead.

It can mean either, depending on context.

In this sentence, it clearly means to get up (out of bed), because of:

• по выходным = on weekends
• поздно = late

So the natural meaning is to get up late.

If someone literally rises from a chair, вставать can also mean to stand up. Context tells you which meaning is intended.

Because поздно is an adverb, and it modifies the verb вставать.

It tells us how / when the person gets up:

• вставать поздно = to get up late

An adjective like поздний would describe a noun:

• поздний ужин = a late dinner
• поздний поезд = a late train

So here an adverb is needed, not an adjective.

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

The original sentence is natural:

• По выходным я люблю вставать поздно.

But these are also possible:

• Я люблю вставать поздно по выходным.
• Я люблю по выходным вставать поздно.
• Поздно вставать по выходным я люблю. (more marked, with emphasis)

The original version puts по выходным first, which gives the time setting right away: as for weekends...

Not always.

Because люблю already shows I through its verb ending, Russian can often omit я if the subject is clear:

• По выходным люблю вставать поздно.

That said, keeping я is completely normal and often sounds clearer, especially for learners or when the speaker wants a slightly more explicit statement.

So:

• По выходным я люблю вставать поздно. = clear, neutral
• По выходным люблю вставать поздно. = also natural if context makes the subject obvious

The main stresses are:

По выходны́м я люблю́ встава́ть по́здно.

A rough pronunciation guide:

• по выходны́м = pa vy-kha-DNYM
• я люблю́ = ya lyub-LYU
• встава́ть = fsta-VAT'
• по́здно = POZD-na

A couple of useful pronunciation notes:

• я often sounds more like ya
• вставать begins with a consonant cluster, which can feel tricky at first
• the stress in Russian matters a lot, so it is worth learning words together with stress

They are related, but not the same.

• просыпаться = to wake up
• вставать = to get up, to rise, to get out of bed

So:

• You can проснуться or просыпаться first.
• Then you встать or вставать.

In English, wake up and get up are also different, and Russian keeps that same distinction.

So this sentence is specifically about liking to get up late, not just wake up late.