Мій комп’ютер сучасний, і він працює швидко.

Because комп’ютер is a masculine singular noun in Ukrainian.

Possessive words like my change their form to match the gender and number of the noun:

• мій = my (masculine)
• моя = my (feminine)
• моє = my (neuter)
• мої = my (plural)

So:

• мій комп’ютер = my computer
• моя книга = my book
• моє місто = my city
• мої друзі = my friends

In Ukrainian, every noun has a grammatical gender: masculine, feminine, or neuter. This does not always have anything to do with real-life sex or natural gender.

Комп’ютер is grammatically masculine, which is why it takes:

• мій instead of моя / моє
• сучасний instead of сучасна / сучасне
• він instead of вона / воно

A good clue is that many masculine nouns in the nominative singular end in a consonant, and комп’ютер does.

Because сучасний is an adjective, and it describes the noun комп’ютер.

• сучасний = modern
• сучасно = in a modern way / modernly

Here, you are saying The computer is modern, so you need the adjective form that agrees with комп’ютер:

• masculine singular nominative: сучасний

Compare:

• сучасний комп’ютер = a modern computer
• це сучасно = this is modern / this is done in a modern way

In Ukrainian, the verb to be is usually omitted in the present tense.

So where English says:

• My computer is modern

Ukrainian normally says:

• Мій комп’ютер сучасний

There is no present-tense є here in normal speech for this kind of sentence.

So the structure is often:

• noun + adjective
• literally: My computer modern
• meaning: My computer is modern

This is completely normal Ukrainian grammar.

Most of the sentence is in the nominative case, because it is the basic subject-predicate structure.

• Мій — nominative masculine singular
• комп’ютер — nominative singular
• сучасний — nominative masculine singular, matching комп’ютер
• він — nominative singular pronoun
• працює — verb
• швидко — adverb, so it does not behave like a noun/adjective in a case pattern here

The first clause is basically:

• Мій комп’ютер сучасний
  = My computer is modern

The second clause is:

• він працює швидко
  = it works quickly

Yes. In Ukrainian, pronouns agree with the grammatical gender of the noun, not with whether the thing is actually male or female.

Since комп’ютер is masculine, the pronoun is:

• він = he / it (for masculine nouns)

In English, we would usually say it for a computer. In Ukrainian, він is the normal grammatical equivalent because the noun is masculine.

So:

• комп’ютер ... він
• книга ... вона
• місто ... воно

Yes, absolutely. That is very natural.

Ukrainian often omits subject pronouns when the meaning is already clear from context or from the verb form.

So both are possible:

• Мій комп’ютер сучасний, і він працює швидко.
• Мій комп’ютер сучасний і працює швидко.

The version with він can sound a little more explicit or slightly more balanced because the sentence has two full clauses. But omitting it is also very common.

Because і is joining two clauses, not just two single words.

The clauses are:

1. Мій комп’ютер сучасний
2. він працює швидко

Each clause has its own subject and predicate, so a comma is normally used before і.

Compare:

• Мій комп’ютер сучасний і швидкий.
  No comma, because сучасний and швидкий are just two adjectives.

• Мій комп’ютер сучасний, і він працює швидко.
  Comma, because these are two clauses.

Yes. Працює comes from працювати, which usually means to work.

With machines, devices, and computers, працювати often means:

• to work
• to function
• to operate
• sometimes close to to run

So:

• Комп’ютер працює = The computer works / is working / is functioning

In this sentence:

• він працює швидко = it works quickly

This sounds natural in Ukrainian.

Because швидко is an adverb, and it describes how the computer works.

• швидкий = fast (adjective)
• швидко = quickly / fast (adverb)

Here you are describing the verb працює:

• працює швидко = works quickly

If you wanted to describe the noun комп’ютер, you would use the adjective:

• швидкий комп’ютер = a fast computer
• Мій комп’ютер швидкий = My computer is fast

So:

• adjective for nouns: швидкий
• adverb for verbs: швидко

Працює is the 3rd person singular present tense form of працювати.

That means it corresponds to:

• he works
• she works
• it works

Here it matches він:

• він працює = he/it works

A few present tense forms of працювати are:

• я працюю = I work
• ти працюєш = you work
• він/вона/воно працює = he/she/it works
• ми працюємо = we work
• ви працюєте = you work
• вони працюють = they work

The apostrophe in Ukrainian is not like the English apostrophe for possession or contractions. It has a pronunciation function.

In комп’ютер, the apostrophe shows that the consonant before ю is not softened and that the ю is pronounced more like yu.

So комп’ютер is pronounced roughly like:

• kom-PYU-ter

The apostrophe helps separate the sounds so you do not blend them in the wrong way.

This is a normal spelling feature in Ukrainian words such as:

• об’єкт
• ім’я
• п’ять
• комп’ютер

Ukrainian word order is more flexible than English word order, but some versions sound more natural than others.

The original sentence:

• Мій комп’ютер сучасний, і він працює швидко.

is clear and natural.

You could also say:

• Мій комп’ютер сучасний і працює швидко.
• Мій комп’ютер працює швидко, і він сучасний.

But changing the order may shift the emphasis slightly.

For example:

• starting with Мій комп’ютер сучасний emphasizes that it is modern
• starting with Мій комп’ютер працює швидко emphasizes performance first

So word order can change, but the original is a very standard and learner-friendly version.

Because both words must agree with комп’ютер.

In Ukrainian, modifiers agree with the noun in:

• gender
• number
• case

Here the noun is:

• masculine
• singular
• nominative

So both words match it:

• мій комп’ютер
• сучасний комп’ютер

This kind of agreement is one of the most important patterns in Ukrainian grammar.

Yes, that is close and understandable, but in natural English, works quickly is usually a smoother match for працює швидко in this sentence.

So the best natural translation is usually:

• My computer is modern, and it works quickly.

You might also see:

• My computer is modern, and it runs fast.
• My computer is modern, and it functions quickly.

But працює швидко most directly means works quickly / works fast.