Ліміт гігабайтів низький, і додатковий пакет інтернету дорогий.

In Ukrainian, the present-tense form of to be is usually omitted.

So:

• Ліміт гігабайтів низький = The gigabyte limit is low
• додатковий пакет інтернету дорогий = the additional internet package is expensive

You can think of it literally as:

• Limit of gigabytes low
• additional package of internet expensive

Ukrainian does have є for is/there is, but in simple present-tense sentences like this, leaving it out is the normal style.

Because after ліміт (limit), Ukrainian uses the genitive to show limit of what?

• ліміт = limit
• гігабайтів = of gigabytes

So ліміт гігабайтів literally means limit of gigabytes.

This is very common in Ukrainian. Compare:

• склянка води = a glass of water
• чашка чаю = a cup of tea
• ліміт гігабайтів = a limit of gigabytes

Here гігабайтів is genitive plural.

For the same basic reason: пакет інтернету means package of internet.

• пакет = package / bundle
• інтернету = of internet

So інтернету is in the genitive singular.

In telecom language, this kind of phrase is very natural. It refers to an internet/data bundle, not a physical package.

Because they are masculine singular nominative adjective forms.

They agree with the nouns they describe:

• ліміт is masculine singular, so низький
• пакет is masculine singular, so додатковий and дорогий

So the agreement is:

• ліміт ... низький
• додатковий пакет ... дорогий

If the noun were feminine or plural, the adjective form would change.

Because this sentence joins two separate clauses:

1. Ліміт гігабайтів низький
2. додатковий пакет інтернету дорогий

Each clause has its own subject and predicate idea, so Ukrainian normally uses a comma before і in this kind of compound sentence.

So the comma is not random punctuation; it marks the boundary between two coordinated statements.

No. In this context, пакет means a plan, bundle, or add-on package, especially in mobile or internet service language.

So додатковий пакет інтернету means something like:

• an extra internet package
• an additional data bundle
• an extra internet add-on

This is a very normal commercial/service-provider use of пакет.

No, Ukrainian word order is fairly flexible. The sentence as written is natural and neutral:

• Ліміт гігабайтів низький, і додатковий пакет інтернету дорогий.

But Ukrainian can often move things around for emphasis. For example, you could emphasize the package:

• Додатковий пакет інтернету дорогий, а ліміт гігабайтів низький.

The original version sounds like a straightforward statement of two facts.

Because Ukrainian has no articles.

So:

• ліміт can mean the limit or a limit
• пакет can mean the package or a package

You understand which one is meant from context. In this sentence, English naturally uses the:

• The gigabyte limit is low, and the additional internet package is expensive.

But Ukrainian does not need separate words for that.

Yes.

• низький = low
• дорогий = expensive / costly

So:

• ліміт ... низький = the limit is low
• пакет ... дорогий = the package is expensive

These are the ordinary, standard adjectives you would expect in this kind of sentence.

Yes. Додатковий often means:

• additional
• extra
• supplementary

So додатковий пакет інтернету can be understood as:

• additional internet package
• extra internet package
• extra data bundle

In natural English, extra may sound more idiomatic in some contexts, but the Ukrainian word itself is perfectly standard.

It is basically:

[noun phrase] + [adjective], і [noun phrase] + [adjective]

More specifically:

• Ліміт гігабайтів = subject noun phrase
• низький = predicate adjective
• і = and
• додатковий пакет інтернету = second subject noun phrase
• дорогий = second predicate adjective

So it is a very useful pattern for describing things in Ukrainian:

• X low, and Y expensive
• with the present-tense is/are understood rather than spoken.