Увечері я дивлюся серіал з друзями.

Увечері means “in the evening”.

Grammatically, it’s treated as a single adverb, not as “у + вечір” written separately. It answers the question “коли?” (when?).

So:

• Увечері = “in the evening” (adverb)
• It does not require any case ending after it, because it isn’t a separate preposition + noun phrase in this form.

Both увечері and ввечері are used in real life and mean the same thing: “in the evening”.

• Увечері is the more standard and common form in modern literary Ukrainian.
• Ввечері is also heard, especially in speech, and isn’t usually considered wrong, but увечері is safer in writing.

So for learners, stick with Увечері.

Yes, you can say вечором, and it is also common in speech.

• Увечері and вечором both mean “in the evening”.
• Увечері sounds a bit more neutral/standard.
• Вечором is also correct; it can sound a bit more colloquial in some contexts.

Example:

• Увечері я дивлюся серіал з друзями.
• Вечором я дивлюся серіал з друзями.

Both are acceptable.

You can drop я here, and the sentence will still be correct:

• Увечері дивлюся серіал з друзями.

In Ukrainian, the verb ending -юся in дивлюся already tells you the subject is “I” (1st person singular).

Including я:

• Often adds slight emphasis to the subject: I (as opposed to someone else) watch a series…
• Is very natural and common in speech and writing.

So both are correct:

• With emphasis/clarity: Увечері я дивлюся серіал з друзями.
• More neutral/short: Увечері дивлюся серіал з друзями.

The infinitive is дивитися = “to watch / to look (at)”, and it is inherently a reflexive verb with -ся.

• -ся / -сь is a reflexive/postfix marker attached to verbs.
• In many Ukrainian verbs, -ся is part of the normal verb form and doesn’t mean literal “myself”.
  Here, дивитися just means “to watch”, not “to watch myself”.

Conjugation (present tense) looks like this:

• я дивлюся – I watch
• ти дивишся – you watch
• він / вона / воно дивиться – he/she/it watches
• ми дивимося – we watch
• ви дивитеся – you (pl/formal) watch
• вони дивляться – they watch

So дивлюся is the required 1st person singular form; дивлю by itself is not correct here.

In Ukrainian, the same present tense form is used for both meanings. Context decides.

Я дивлюся серіал can mean:

• “I (usually) watch a series” – a habit/routine, especially with a time adverb like увечері.
• “I am watching a series (right now)” – if the context makes it clear it’s happening at this moment.

In your sentence Увечері я дивлюся серіал з друзями, the presence of увечері makes it sound more like a regular habit:
> In the evenings, I watch a series with friends.

Дивлюся is pronounced approximately like [dyv-LYU-sia] in English-style transcription.

• Stress falls on -лю-: дивЛЮся.
• и = a short, central vowel (not exactly English i in “sit”, but close).
• вл is a consonant cluster [vl].
• ю = [yu] as in “you”.
• ся = [sia] (s + “ya”).

So: ди-вЛЮ-ся → dyv-LYU-sia.

Ukrainian has no articles (no “a”, “an”, “the”).

Серіал here can correspond to:

• “a series / a TV show”
• or “the series / the show”

Which one is intended depends on context, not on any word in the sentence.

Grammatically:

• серіал is masculine, inanimate, singular.
• In the accusative case (as a direct object), inanimate masculine nouns look the same as the nominative:
  • Ном.: серіал
  • Знах. (Acc.): серіал

So дивлюся серіал = “(I) watch a/the series”.

Друзями is the instrumental plural form of друг (“friend”).

Declension of друг (simplified):

• Ном. sing.: друг – a friend
• Ном. plural: друзі – friends
• Інстр. plural: друзями – (with) friends

The preposition з in the meaning “with” normally requires the instrumental case:

• з другом – with (a) friend
• з друзями – with friends

So:

• з друзями literally = “with friends” (instrumental plural).
• That’s why it’s -ями, not друзі.

All three forms (з / із / зі) are the same preposition “from/with”; the choice depends on euphony (how well it sounds).

• з is the basic form.
• із is used before consonant clusters or sometimes before words beginning with a vowel to make pronunciation easier.
• зі is often used before words starting with з-, с-, ж-, ш- or difficult clusters, again for sound.

In your sentence:

• з друзями is perfectly natural and most common.
• із друзями is also possible and accepted.
• зі друзями is less usual here; you’re more likely to hear it in combinations like зі мною, зі школи, etc.

For learners, з друзями is the best default.

Approximate pronunciations with stress:

• серіал → се-рі-А́л → se-ree-AHL

  • Stress on the last syllable: -ал.

• друзями → ДРУ́-зя-ми → DROO-zia-my

  • Stress on дру́-.
  • я after з = “ya”: [zya].

• увечері → у-ВЕ́-че-рі → oo-VE-che-ree

  • Stress on ве́-.
  • ч = [ch] as in “church”.
  • Final -рі = “ree”.

Yes. Ukrainian word order is relatively flexible, and all of these are grammatical:

1. Увечері я дивлюся серіал з друзями.
2. Я увечері дивлюся серіал з друзями.
3. Я дивлюся серіал з друзями увечері.

They all mean essentially the same thing. The differences are nuances of emphasis:

• Starting with Увечері (1) emphasizes when: In the evening, I watch…
• Starting with Я (2, 3) emphasizes who: I, in the evening, watch…
• Moving увечері to the end (3) can give it a slight “afterthought” feel: I watch a series with friends — in the evening.

For a neutral declarative sentence, (1) and (2) are especially common.

In Ukrainian, a short adverbial like Увечері at the start of the sentence is usually not set off by a comma.

So:

• Correct: Увечері я дивлюся серіал з друзями.
• Writing Увечері, я дивлюся… is not standard and would look incorrect or at least strange in formal writing.

Commas before the main subject are used for longer or more complex introductory phrases, not for a simple one-word adverb like увечері.