Nemoj da vežbaš ako te boli mišić.

A very common way to make a negative command in Serbian is:

nemoj + da + present tense

So here:

• nemoj = don’t (to one person)
• da vežbaš = literally something like that you exercise, but in natural English it works like to exercise

So Nemoj da vežbaš means Don’t exercise.

This pattern is extremely common in everyday Serbian.

Because Serbian often uses da + present tense where English would use an infinitive.

English:

• Don’t exercise

Serbian:

• Nemoj da vežbaš

Here vežbaš is the 2nd person singular present form, because the sentence is addressed to you (ti), even though ti is not stated.

Yes. Ne vežbaj is also correct and means the same thing: Don’t exercise.

The difference is mostly in style:

• Ne vežbaj = shorter, more direct
• Nemoj da vežbaš = very common, often a little softer or more conversational

Both are natural Serbian.

Ako means if.

So the second part of the sentence introduces a condition:

• ako te boli mišić = if your muscle hurts / if a muscle hurts

Serbian uses ako very much like English uses if.

Because the verb boleti works differently from English to hurt.

In Serbian, the person who feels the pain is usually expressed with an object pronoun, not as the grammatical subject:

• boli me = it hurts me
• boli te = it hurts you
• boli ga/je = it hurts him/her

So in te boli mišić, te means you in the object form, not the subject form.

That is why ti would be wrong here.

Because boli agrees with mišić, which is singular.

In this clause:

• mišić = the grammatical subject
• te = object pronoun

So literally the structure is closer to:

• A muscle hurts you

Since mišić is singular, the verb must also be singular:

• mišić boli

If the subject were plural, then you would use bole:

• Ako te bole mišići = If your muscles hurt

The singular is fine if you mean one muscle.

So:

• ako te boli mišić = if a muscle hurts / if one muscle hurts

If you mean muscles in general, then plural is often more natural:

• ako te bole mišići = if your muscles hurt

So the original sentence is correct, but it sounds most natural when talking about pain in one particular muscle.

Because Serbian does not have articles like English a/an/the.

So mišić can mean:

• a muscle
• the muscle
• sometimes just muscle

The exact meaning depends on context.

That is very normal in Serbian, and learners often have to get used to understanding nouns without articles.

Yes, in the first clause it is omitted.

In vežbaš, the ending -š already shows that the subject is you (ti), so Serbian usually leaves ti out unless it needs emphasis.

So:

• (ti) vežbaš = you exercise

But in the second clause, te is not an omitted subject. It is an actual pronoun meaning you in the object form:

• te boli mišić

So the sentence contains:

• an implied ti in vežbaš
• an expressed object pronoun te in te boli

Yes. Serbian allows that very naturally.

You can say:

• Nemoj da vežbaš ako te boli mišić.
• Ako te boli mišić, nemoj da vežbaš.

Both are correct. The meaning stays the same. The second version puts the condition first, which can sound a little more emphatic or organized.

Not always. Vežbati can mean:

• to exercise
• to practice
• to rehearse

So its exact meaning depends on context.

In this sentence, because of mišić and pain, it clearly means to exercise / work out.

A rough guide:

• vežbaš ≈ VEZH-bash
  • ž sounds like the s in measure
• mišić ≈ MEE-shich
  • š sounds like sh
  • ć is a soft sound, somewhat like a very soft ch

So:

• vežbaš = VEZH-bash
• mišić = MEE-shich

The exact Serbian sounds are a bit more precise than English approximations, but this is a good start.