Lijeva ruka me boli.

Because lijeva is an adjective, and Croatian adjectives must agree with the noun they describe in:

• gender
• number
• case

Here, ruka is feminine singular nominative, so the adjective also has to be feminine singular nominative:

• lijev = masculine
• lijeva = feminine
• lijevo = neuter

So lijeva ruka is the correct matching form.

Because ruka is the grammatical subject of the verb boli.

With boljeti in this kind of sentence, Croatian usually treats the thing that hurts as the subject:

• Glava me boli.
• Noga me boli.
• Lijeva ruka me boli.

So ruka stays in the nominative: ruka, not ruku.

If you used ruku, that would be accusative, which is not what this sentence needs.

Me is the short, unstressed accusative form of ja.

So in this sentence, me means me as the person affected by the pain.

The structure is basically:

• lijeva ruka = the body part that hurts
• me = the person who feels the pain
• boli = hurts/aches

So Croatian expresses this as something like the left hand/arm hurts me.

Because the subject is singular: ruka.

The verb agrees with the thing that hurts, not with me.

• Lijeva ruka me boli. = singular subject → boli
• Ruke me bole. = plural subject → bole

So me does not control the verb form; ruka does.

It is correct and natural, but Boli me lijeva ruka is also very common.

The difference is mainly focus:

• Lijeva ruka me boli. → emphasizes the left hand/arm
• Boli me lijeva ruka. → more neutral, often more conversational

Croatian word order is flexible, but short pronouns like me are clitics, so they usually appear near the beginning of the sentence, after the first stressed element or phrase.

That is why:

• Lijeva ruka me boli. ✔
• Boli me lijeva ruka. ✔
• Me boli lijeva ruka. ✘ in standard word order

There are two separate reasons:

1. Croatian has no articles, so there is no direct word for the or a.
2. With body parts, Croatian often omits the possessive pronoun when ownership is obvious.

So Lijeva ruka me boli naturally means my left hand/arm hurts without needing moja.

You can say:

• Moja lijeva ruka me boli.

But that sounds more emphatic, as if you are stressing my left hand specifically.

It can mean either, depending on context.

This is a common point for English speakers. Croatian ruka often covers the whole upper limb more broadly than English does.

So Lijeva ruka me boli could mean:

• My left hand hurts
• My left arm hurts

If you need to be more specific, Croatian has narrower words such as:

• šaka = hand
• dlan = palm
• podlaktica = forearm
• nadlaktica = upper arm

But in everyday speech, ruka is very common.

Yes, but it changes the tone.

• me = short, neutral, unstressed form
• mene = full, stressed form

In a normal sentence, me is the natural choice:

• Lijeva ruka me boli.

You would use mene for emphasis, contrast, or special sentence structure, for example:

• Mene lijeva ruka boli, a njega desna.

So for an ordinary statement, me is better.

You keep the body part the same and change the pronoun:

• Lijeva ruka me boli. = my left hand/arm hurts
• Lijeva ruka te boli. = your left hand/arm hurts
• Lijeva ruka ga boli. = his/it hurts
• Lijeva ruka je boli. = her hurts
• Lijeva ruka nas boli. = our hurts
• Lijeva ruka vas boli. = your hurts
• Lijeva ruka ih boli. = their hurts

The verb stays boli as long as ruka is singular.

Then the subject becomes plural, and the verb usually becomes bole.

For example:

• Ruke me bole. = my hands/arms hurt
• Noge me bole. = my legs hurt
• Oči me bole. = my eyes hurt

So the main pattern is:

• singular body part → boli
• plural body part → bole

Yes. That is completely normal.

• Ruka me boli. = my hand/arm hurts
• Lijeva ruka me boli. = my left hand/arm hurts

You add lijeva only when the side matters or when you want to be more specific. If context already makes it clear which side you mean, speakers may simply say Ruka me boli.