Popravite držanje tijela tako što prilagodite naslon za leđa.

Yes. Both popravite and prilagodite are imperative forms, so the sentence is giving an instruction or command.

In Croatian, the -te ending usually shows:

• plural you: speaking to more than one person
• or formal you: speaking politely to one person

So this sentence is addressing either:

• a group of people, or
• one person formally

The singular informal versions would be:

• Popravi držanje tijela tako što prilagodi naslon za leđa.

This kind of wording is very common in instructions, manuals, health advice, and workplace guidance.

Tijela is genitive singular of tijelo (body).

The phrase držanje tijela literally means holding of the body, and idiomatically it means body posture or simply posture.

This is a very common Croatian structure:

• a noun + another noun in the genitive
• often similar to English X of Y

Examples:

• boja zida = the color of the wall
• vrata automobila = the car door / the door of the car
• držanje tijela = posture / the holding of the body

So držanje is the main noun, and tijela specifies whose/what kind of holding.

Držanje comes from the verb držati (to hold, keep), but here it functions as a noun meaning:

• bearing
• posture
• the way you hold yourself

So in this sentence, držanje tijela is best understood as:

• posture
• body posture

It does not mean holding in the everyday English sense of physically carrying something. In this context it refers to physical alignment.

Tako što means something like:

• by
• by means of
• in such a way that
• by doing...

In this sentence:

• Popravite držanje tijela tako što prilagodite naslon za leđa.

the idea is:

• Improve/correct your posture by adjusting the backrest.

So tako što + verb is a common Croatian way to explain how something is done.

A very literal breakdown would be:

• tako = in that way / so
• što = that / by the fact that

But as a whole, you should learn tako što as a fixed expression meaning by doing X.

Yes. Croatian has a few ways to express by doing something, but tako što is one of the clearest and most common in instructional language.

For example, Croatian can also use:

• prilagodbom naslona za leđa = by adjusting the backrest
  This uses an instrumental-like verbal noun structure and sounds more formal or condensed.

So you might also see something like:

• Popravite držanje tijela prilagodbom naslona za leđa.

But your original sentence with tako što sounds very natural and easy to understand.

Because here prilagoditi is being used as a transitive verb: you are adjusting something.

• prilagoditi nešto = to adjust/adapt something

So:

• prilagodite naslon za leđa = adjust the backrest

By contrast:

• prilagoditi se = to adapt oneself / to get used to / to adjust oneself

Examples:

• Prilagodite naslon. = Adjust the backrest.
• Prilagodite se situaciji. = Adapt to the situation.

So in your sentence, there is a direct object, naslon za leđa, which is why there is no se.

It is in the accusative, because it is the direct object of prilagodite.

The base noun is:

• naslon = backrest, support, rest

Masculine inanimate nouns like naslon usually have:

• nominative singular: naslon
• accusative singular: naslon

So nominative and accusative look the same here.

That is why you see:

• prilagodite naslon = adjust the backrest

Here za means for.

So:

• naslon za leđa = back support / backrest
• literally: support for the back

This is a common noun-building pattern in Croatian:

• čaša za vodu = glass for water
• stalak za knjige = stand for books
• krema za ruke = hand cream
• naslon za leđa = backrest

So za + accusative often describes purpose: something intended for something.

Great question. Leđa is one of those Croatian nouns that is normally used only in the plural. English learners often notice this quickly.

So:

• leđa = back
• grammatically plural, but meaning a single body part in English

This is similar to how some languages treat words like scissors or pants as plural.

You will often see:

• bol u leđima = back pain
• naslon za leđa = backrest
• ležati na leđima = lie on one’s back

So even though English says back, Croatian usually uses the plural form leđa.

Several verbs are possible, but they are not exactly identical.

• popraviti = to fix, repair, improve, correct
• ispraviti = to straighten, correct, make right
• poboljšati = to improve

In this sentence, popravite držanje tijela sounds natural in practical advice, especially in a broad sense of improve/correct your posture.

Other possibilities:

• Ispravite držanje tijela...
  This can sound more like straighten/correct your posture.
• Poboljšajte držanje tijela...
  This means improve your posture and sounds a bit softer or more general.

So popravite is fine, but it is not the only possible choice.

Both popravite and prilagodite are perfective imperatives:

• popraviti
• prilagoditi

Perfective verbs are very common in instructions when the speaker focuses on achieving a result:

• fix it
• adjust it
• complete the action

In practical guidance, Croatian often prefers perfective imperatives because they sound goal-oriented:

• Namjestite sjedalo. = Adjust the seat.
• Otvorite prozor. = Open the window.
• Provjerite zaslon. = Check the screen.

Imperfective forms would usually sound different in nuance and are less likely in this kind of concise instruction.

It can be added, but it is usually omitted because the verb ending already tells you the subject.

So:

• Popravite držanje tijela... is the normal version.
• Vi popravite držanje tijela... is possible, but it adds emphasis.

Croatian often leaves subject pronouns out unless they are needed for:

• contrast
• emphasis
• clarity

So in neutral instructions, omitting vi is completely normal.

Yes, Croatian word order is more flexible than English word order, although not every version sounds equally natural.

The original:

• Popravite držanje tijela tako što prilagodite naslon za leđa.

This is clear and natural.

You could also say:

• Držanje tijela popravite tako što prilagodite naslon za leđa.

This puts more focus on držanje tijela.

But the original order is probably the most neutral and natural for an instruction. Croatian word order often changes for emphasis, topic, or style rather than basic grammatical necessity.

It sounds understandable and natural enough, especially in instructional or ergonomic advice.

A Croatian speaker might also phrase it in slightly different ways, for example:

• Poboljšajte držanje tijela tako da prilagodite naslon za leđa.
• Ispravite držanje tijela prilagodbom naslona za leđa.
• Za pravilno držanje tijela prilagodite naslon za leđa.

So your sentence is good Croatian, but there are several natural alternatives depending on tone:

• direct instruction
• formal advice
• health/ergonomic guidance

A fairly literal breakdown is:

• Popravite = correct / improve / fix
• držanje = posture / holding
• tijela = of the body
• tako što = by / by doing so that
• prilagodite = adjust
• naslon = support / rest / backrest
• za leđa = for the back

So very literally:

• Correct the holding of the body by adjusting the support for the back.

A natural English translation would be:

• Improve your posture by adjusting the backrest.
• Correct your posture by adjusting the backrest.