Learn Hardcore Russian: У моего мужа болит горло, поэтому он пьёт тёплый чай. - My husband's throat hurts, so he is drinking warm tea.

If you just say Мой муж болит горло, it’s wrong.
The verb болеть (to hurt / to ache) in this construction doesn’t take the person as the subject; instead:

the person is expressed with у + genitive: у моего мужа
the body part is the grammatical subject: горло

Why is it моего мужа and not мой муж after у?

The preposition у always takes the genitive case.

Nominative (dictionary form): мой муж – my husband
Genitive (after у): у моего мужа – at my husband / my husband has

So both words change:

мой → моего (masculine/neuter genitive singular)
муж → мужа (genitive singular)

Formally:

у кого? – у моего мужа

In болит горло, which word is the subject of the verb?

The subject is горло.

горло is neuter singular in the nominative case
The verb болит is 3rd person singular and agrees with горло in number (singular)

So grammatically, the sentence is:

(У моего мужа) – “at my husband” (experiencer, not subject)
горло – subject
болит – verb

Literally: “The throat hurts (at my husband).”

Why is горло in the nominative and not some other case?

Because горло is the grammatical subject of the verb болит.

The typical pattern for this pain-construction is:

У кого?
- что болит?
  - У меня болит голова. – I have a headache.
  - У него болят зубы. – His teeth hurt.
  - У моего мужа болит горло. – My husband has a sore throat.

The body part that hurts (голова, зубы, горло) is in the nominative case, since it’s the subject of болит / болят.

Could we also say Моего мужа болит горло without у?

No, that is ungrammatical.

To express “X has a sore Y” in Russian, you must use:

У + genitive of the person
- болит / болят
  - nominative body part

Correct examples:

У моего мужа болит горло.
У сына болит живот.
У меня болят ноги.

Leaving out у breaks this pattern and sounds wrong to native speakers.

Why is there a comma before поэтому?

The sentence has two clauses:

У моего мужа болит горло – main clause 1 (reason)
он пьёт тёплый чай – main clause 2 (result)

Поэтому (“therefore / so”) is a linking word that introduces the result clause. In Russian, when you join such clauses, you normally put a comma before поэтому:

…, поэтому …

So:

У моего мужа болит горло, поэтому он пьёт тёплый чай.
= My husband has a sore throat, so he’s drinking warm tea.

What is the difference between поэтому and потому что?

They both express cause and effect, but they work in opposite directions:

поэтому = therefore, so
- Clause A (reason), поэтому clause B (result)
- У моего мужа болит горло, поэтому он пьёт тёплый чай.
  My husband has a sore throat, so he’s drinking warm tea.
потому что = because
- Clause A (result) потому что clause B (reason)
- Он пьёт тёплый чай, потому что у него болит горло.
  He’s drinking warm tea because he has a sore throat.

So you cannot just swap поэтому and потому что without also changing the order of the clauses.

Why is чай in the form чай, not чая or something else?

Чай is masculine and inanimate.

In Russian, for masculine inanimate nouns, the accusative is the same as the nominative:

Nominative: чай
Accusative: чай (no change)

In the sentence:

он пьёт (что?) тёплый чай

The question что? (“what?”) tells you this is the accusative object of пьёт, but the form happens to be identical to the nominative.

Why is it пьёт, not something like пьет or another verb form?

A few points:

Spelling:
- The correct spelling is пьёт (with ё), but in everyday writing Russians often write пьет (without the dots). It is still pronounced пьёт.
Form:
- пьёт is the 3rd person singular present tense of the verb пить (imperfective) – to drink.
- Person: he
- Number: singular
Aspect:
- Imperfective is used here because we’re describing what he is doing (in general / now) as a response to his sore throat, not a single completed act of drinking.

So он пьёт тёплый чай = he is drinking / (he) drinks warm tea.

Why is it тёплый чай and not тёплое чай?

Adjectives in Russian must agree with the noun they describe in gender, number, and case.

чай is masculine, singular, accusative.
The matching masculine accusative singular adjective ending is -ый (for hard stems), so we get тёплый.

Patterns:

masculine: тёплый чай
feminine: тёплая вода
neuter: тёплое молоко
plural: тёплые напитки

So тёплый чай = warm tea with proper gender agreement.

What is the difference between тёплый чай and горячий чай?

Both describe temperature, but not the same:

тёплый чай – warm tea
- Pleasantly warm, not too hot.
- Good when you’re sick; comfortable to drink.
горячий чай – hot tea
- Quite hot, maybe just after boiling.
- Could burn your mouth if you’re not careful.

In your sentence, тёплый чай makes sense because with a sore throat, people usually prefer warm (not burning hot) tea.

How are моего and тёплый pronounced, and why do we see ё?

Pronunciation:

моего: [ма-е-ВО] or often [маво] in fast speech
- Stress on the last syllable: моего́
тёплый: [ТЁ-плый]
- Stress on the first syllable: тё́плый

About ё:

The letter ё always indicates the sound [yo] and is always stressed.
In normal Russian printing, people often write е instead of ё, so you might see теплый instead of тёплый, but it is still pronounced [тёплый].

In careful or educational texts, ё is written with dots to make pronunciation clear.