Želim da ojačam mišiće.

A rough English-style pronunciation is:

ZHE-lim da o-YA-cham MEE-shee-che

A few key sounds:

• Ž sounds like the s in measure
• j sounds like English y
• č sounds like ch in church
• ć is a softer version of č
• Serbian spelling is very phonetic, so words are usually pronounced the way they are written

So:

• Želim ≈ ZHE-lim
• ojačam ≈ o-YA-cham
• mišiće ≈ MEE-shee-che

Because Serbian often leaves out subject pronouns when the verb already makes the subject clear.

Here, želim ends in -m, which shows first person singular: I want.

So:

• Želim da ojačam mišiće = I want to strengthen muscles
• Ja želim da ojačam mišiće = same meaning, but ja adds emphasis, like I want to...

In this sentence, da introduces the second verb clause after želim.

English uses to:

• I want to strengthen...

Serbian usually uses:

• želim da + present-tense form

So:

• želim da ojačam literally looks more like I want that I strengthen
• but in natural English it simply means I want to strengthen

This da + verb structure is extremely common in Serbian.

Because in modern Serbian, after verbs like želim, the normal pattern is:

želim da + present-form verb

So:

• Želim da ojačam... is the natural Serbian structure

An infinitive like ojačati exists, but Serbian usually prefers da + verb here. A bare infinitive after želim sounds less typical in Serbian and more natural in Croatian.

Yes, ojačam is a present-form verb, but after da it does not mean a normal present action like I am strengthening right now.

Here it expresses something wanted, intended, or aimed at:

• Želim da ojačam... = I want to strengthen...

So even though the form is present, the meaning is closer to:

• intention
• goal
• future result

This is normal in Serbian.

This is a question of aspect, which is very important in Serbian.

• ojačam comes from ojačati and is perfective
• jačam comes from jačati and is imperfective

Very roughly:

• ojačam focuses on the result: becoming stronger, making something stronger
• jačam focuses on the process: strengthening, working on getting stronger

So:

• Želim da ojačam mišiće = I want to strengthen my muscles / make them stronger
• Želim da jačam mišiće = I want to work on strengthening my muscles / keep building strength

Both can be natural, but ojačam points more to the achieved outcome.

Because mišiće is the accusative plural, used for the direct object of the verb.

Here, mišiće is what you want to strengthen, so it must be in the object case.

Compare:

• mišići = nominative plural, used for the subject
• mišiće = accusative plural, used for the object

Examples:

• Mišići su jaki. = The muscles are strong.
• Želim da ojačam mišiće. = I want to strengthen the muscles / my muscles.

Serbian often leaves out possessives like my, especially with body parts, when the meaning is obvious from context.

So mišiće can mean:

• muscles
• the muscles
• my muscles

In this sentence, most people will naturally understand it as my muscles, because the speaker is talking about their own goal.

This is very normal in Serbian and not considered incomplete.

Correct: Serbian has no articles like a or the.

So mišiće by itself can mean:

• muscles
• the muscles
• sometimes even my muscles, depending on context

Serbian relies on context much more than English does for this kind of meaning.

Yes. Serbian word order is more flexible than English word order.

The most neutral version is:

• Želim da ojačam mišiće.

But you could also say:

• Mišiće želim da ojačam.

That version puts more emphasis on mišiće.

The meaning stays basically the same, but the focus changes. English usually cannot move words around as freely without sounding strange, but Serbian can.

Želim is correct and natural, but it sounds a little more deliberate or formal than everyday speech.

In casual conversation, people often say:

• Hoću da ojačam mišiće.

Very roughly:

• želim = I want / I wish / I desire
• hoću = I want / I’m going to / I intend to

So:

• Želim da ojačam mišiće sounds perfectly good
• Hoću da ojačam mišiće sounds a bit more conversational

In a fitness context, another common phrase is:

• Želim da izgradim mišiće = I want to build muscle / build muscles

But the original sentence is completely natural.