Learn Hardcore Ukrainian: У неї висока температура, тому вона п’є багато води. - She has a high temperature, so she drinks a lot of water.

Ukrainian commonly expresses possession with the pattern у/в + Genitive + (є) + noun, literally “at/with someone there is.” So У неї висока температура = “She has a high fever.”
You can say Вона має високу температуру, and it’s correct, but мати (“to have”) sounds more formal/bookish or emphatic in many contexts. The у неї… construction is the most natural, everyday way to say “she has.”

What case is неї, and why not її?

Неї is the Genitive form of “she,” used after a preposition. With possession via у/в, you must use the Genitive: у неї (“at her”).
Її is used:

as a possessive adjective: її книга (her book)
and as a direct object without a preposition: Я бачу її (I see her)
After a preposition, use the “stressed” forms: у мене, у тебе, у нього, у неї, у нас, у вас, у них.

Why is there no є after у неї?

In present‑tense existential statements, є (“there is/are”) is often omitted: У неї висока температура.
Include є for emphasis/contrast or clarity: У неї є висока температура, а у нього — ні (She has a high fever, and he doesn’t).

Why У and not В at the start?

Ukrainian alternates у/в for euphony. At the beginning of a sentence, у is very common, and generally у is preferred next to other consonants to avoid clunky clusters. В неї isn’t wrong, but У неї sounds smoother here.

Why is there a comma before тому?

Because the sentence has two independent clauses:
1) У неї висока температура (She has a high fever)
2) тому вона п’є багато води (therefore she drinks a lot of water)
In such “cause → result” sequences, you separate the clauses with a comma before тому.

What’s the difference between тому and тому що?

тому = “therefore/so” and introduces the result clause: …, тому вона п’є…
тому що = “because” and introduces the reason clause: Вона п’є…, тому що у неї висока температура.
Same logic, opposite direction.

How is п’є formed, and what does the apostrophe mean?

П’є is 3rd‑person singular present of пити (to drink). The apostrophe in Ukrainian shows a brief “y” sound [j] before є/я/ю/ї and keeps the preceding consonant hard: п’є ≈ “p-ye.”
Other examples: б’ю (I beat), в’ється (it curls), м’ясо (meat).

Why багато води and not багато воду or багато вод?

After quantity words like багато (“a lot of”), the noun goes to the Genitive:

Mass/uncountable nouns → Genitive singular: багато води, багато молока.
Countable nouns → Genitive plural: багато людей (many people), багато книжок (many books).

Why висока температура (feminine form) and not високий?

Adjectives agree with the noun’s gender/number/case. Температура is feminine singular nominative, so the adjective is висока (feminine), not високий (masculine) or високе (neuter).

Can I say the same idea with “because,” like Вона п’є багато води, бо у неї висока температура?

Yes. Бо is a very common, neutral “because.” You can also use тому що or оскільки. All are fine, with minor style differences: бо (colloquial/neutral), тому що (neutral), оскільки (more formal).

Does температура really mean “fever” in Ukrainian? What about гарячка?

Yes—everyday Ukrainian uses температура to mean “fever,” especially when talking about a measured body temperature: висока температура = “a high fever.”
Гарячка can mean “fever” but also “delirium/mania” (e.g., золота гарячка, “gold fever”), so for medical contexts температура is the safest, most standard choice.

Can I change the word order?

Yes, Ukrainian word order is flexible for emphasis. Some options:

У неї висока температура, тому вона п’є багато води. (neutral)
Вона п’є багато води, бо у неї висока температура. (reason after main clause)
Через високу температуру вона п’є багато води. (fronted cause) All are grammatical; you choose based on what you want to emphasize.

Could I use a perfective verb to describe a specific instance, like “she drank a lot of water”?

Yes:

One completed event: Вона випила багато води. (perfective)
Ongoing/habitual action: Вона пила багато води. (imperfective past)
General present habit: Вона п’є багато води.

Can I omit вона in the second clause?

Often, yes—Ukrainian can drop subject pronouns when the context makes them clear:
У неї висока температура, тому п’є багато води.
However, because 3rd‑person singular verbs don’t show gender, keeping вона avoids ambiguity, especially in standalone sentences.

Any quick pronunciation tips for this sentence?

п’є has a clear “p‑ye” sound due to the apostrophe.
г in багато is a voiced [h], not an English “g”: roughly “ba‑HA‑to.”
вода/води have stress at the end: вода́, води́.
A natural transliteration guide: U neyi vysoka temperatura, tomu vona p’ye bahato vody.
Say it smoothly; the comma marks a slight pause before тому.