Learn Hardcore Ukrainian: Мені боляче, коли болить голова.

Мені = to me (1st person singular, dative case of я “I”)
So Мені боляче literally means: It is painful to me or To me, (it is) painful.

This is similar to other Ukrainian sentences:

Мені холодно. – I am cold. (literally: To me, it is cold.)
Мені сумно. – I am sad. (literally: To me, it is sad.)

So you don’t say Я боляче, because the grammar pattern is “(to someone in dative) + (is) painful,” not “I + painful.”

What exactly is боляче? Is it an adjective or an adverb?

Боляче is an adverb-like predicative form that describes a state: painfully / it hurts / is painful.

You can think of it as:

Functionally similar to English “it hurts” or “it’s painful.”
It doesn’t change for gender, number, or case.
It’s used mostly in impersonal constructions:

Examples:

Мені боляче. – It hurts / I’m in pain.
Йому боляче дивитися на це. – It’s painful for him to look at this.

So in Мені боляче, боляче acts like “is painful,” but Ukrainian doesn’t need a separate verb “to be” in the present tense.

Why doesn’t the sentence say є (like “is”)? Why not Мені є боляче?

In modern Ukrainian, the present tense form of “to be” (є) is usually omitted in simple statements about identity or state.

Мені боляче. – literally To me (it) painful.
The full theoretical form Мені є боляче sounds unnatural in everyday speech.

Other examples:

Я вдома. – I am at home. (not Я є вдома in normal speech)
Він лікар. – He is a doctor.

So the “is” is understood from context; you just don’t say it.

What does болить mean here, and what form is it?

Болить is the 3rd person singular form of the verb боліти – to hurt, to ache, to be in pain.

боліти – to hurt / to ache
(воно) болить – it hurts / it aches

In the sentence:

болить голова = the head hurts / the head aches

So literally, коли болить голова means “when the head hurts.”

Why is it болить голова and not болить мо́я голова (“my head hurts”)?

In Ukrainian, with body parts and personal experiences (pain, injuries, etc.), the possessive pronoun (мій, моя, моє, мої) is often left out, because it’s understood from context.

Болить голова. – My head hurts / the head hurts.
Болить зуб. – My tooth hurts / the tooth hurts.
У мене болить спина. – My back hurts.

You would add the possessive only when you really need to emphasize whose body part it is:

У мене болить саме моя голова, а не шия. – It’s my head that hurts, not my neck.

In the sentence коли болить голова, it’s naturally understood as “when my head hurts” (or “when [someone’s] head hurts,” depending on who is speaking).

Is there a simpler or more common way to say “My head hurts” in Ukrainian?

Yes. A very common everyday pattern is:

У мене болить голова. – My head hurts.

Literally: At me the head hurts.

Other similar sentences:

У мене болить живіт. – My stomach hurts.
У неї болить горло. – Her throat hurts.

Your sentence:

Мені боляче, коли болить голова.
emphasizes the feeling of pain (It’s painful to me) and then explains when – when my head hurts.

What is the difference between Мені боляче and Мені болить голова?

They are related, but not identical:

Мені боляче.
- Focus: general feeling of pain.
- Meaning: It hurts / I’m in pain.
- You don’t say where exactly; it can be emotional or physical.
Мені болить голова.
- Focus: specific body part.
- Meaning: My head hurts.
- You specify what hurts.

Your sentence combines the general and the specific:

Мені боляче, коли болить голова.
I feel pain / it hurts me when my head aches.

Can I change the word order to Коли болить голова, мені боляче?

Yes. That is perfectly correct and natural.

Мені боляче, коли болить голова.
Коли болить голова, мені боляче.

Both mean the same. The second version puts more emphasis on the condition (“when my head hurts”) at the beginning, which in English is also very natural: When my head hurts, I’m in pain.

Ukrainian word order is relatively flexible, especially with clauses connected by коли (“when”).

Does коли here mean exactly “when,” or can it also mean “if”?

Коли primarily means “when” (in time), but in many sentences it can also carry a slight “if/whenever” feel, depending on context.

In Мені боляче, коли болить голова:

Main reading: It hurts me *when my head hurts.*
Nuance: It can also suggest a general rule: Whenever my head hurts, I’m in pain.

But it is not a strict conditional like якщо = “if.”
If you wanted a clear conditional:

Мені боляче, якщо болить голова. – It hurts me if my head hurts.

Here, якщо is more explicitly “if.”

Why is голова in the nominative case? Shouldn’t pain take some other case?

With the verb боліти (“to hurt / ache”), the thing that hurts is normally in the nominative case, because it is the subject of the verb:

Голова болить. – The head hurts.
Зуб болить. – The tooth hurts.
Ноги болять. – The legs hurt. (note болять for plural)

If you include the person:

У мене болить голова. – My head hurts (literally: At me the head hurts.) Here:
голова is still nominative (subject),
у мене is a prepositional phrase telling who is affected.

So болить голова follows the normal pattern: subject (nominative) + verb боліти.

How do I change the sentence if more things hurt, e.g. “my head and my stomach hurt”?

You use the plural form of боліти: болять.

Examples:

У мене болять голова і живіт. – My head and stomach hurt.
У мене болять зуби. – My teeth hurt.
У неї болять коліна. – Her knees hurt.

So:

Singular: болить голова – the head hurts.
Plural: болять ноги – the legs hurt.

How do you pronounce Мені боляче, коли болить голова? Where is the stress?

Approximate pronunciation with stressed syllables in CAPS:

Мені́ – me-NI (stress on ні)
бо́ляче – BO-lya-che (stress on бо́)
ко́ли – KO-ly (stress on ко́)
болить – bo-LYTʹ (stress on лить)
голова́ – ho-lo-VA (stress on the last ва́)

Put together:

me-NI BO-lya-che, KO-ly bo-LYTʹ ho-lo-VA.

That’s a natural, standard Ukrainian pronunciation.