Kendini yorgun hissediyorsan, biraz dinlenmelisin.

Kendini means yourself.

It comes from kendi (self) + -ni, the accusative ending. In this sentence, Turkish uses a reflexive structure with hissetmek:

• kendini yorgun hissetmek = to feel oneself tired

So Turkish often says something closer to if you feel yourself tired rather than just if you feel tired.

Because it functions as the direct object of hissetmek.

Breakdown:

• kendi = self
• kendin = yourself / your self
• kendini = yourself (as a direct object)

In kendini yorgun hissetmek, the thing being felt is yourself, so Turkish marks it as the object.

Because yorgun is acting like a predicate adjective or complement, not like a noun that needs a case ending here.

It describes the state in which you feel yourself:

• kendini yorgun hissetmek = to feel yourself tired
• kendini iyi hissetmek = to feel good
• kendini kötü hissetmek = to feel bad

So yorgun stays in its basic form.

Hissediyorsan can be broken down like this:

• hisset- = feel
• -iyor- = present continuous
• -sa = if
• -n = you (informal singular)

So:

• hissediyorsan = if you are feeling / if you feel

This is a very common Turkish pattern:

• verb stem + tense/aspect + conditional + person

Because -sa / -se is the conditional suffix, meaning if.

Then Turkish adds a personal ending:

• -m = I
• -n = you
• etc.

So:

• gelirsen = if you come
• yorulduysan = if you got tired
• hissediyorsan = if you feel / if you are feeling

The -sa / -se part gives the if meaning, and the final -n shows the subject is you.

Because Turkish often uses the present continuous -iyor for a current, real situation:

• Kendini yorgun hissediyorsan... = If you’re feeling tired...

This sounds natural when talking about how someone feels right now.

A form like hissedersen is also possible in some contexts, but it has a slightly different feel and is less directly about the current state. Hissediyorsan is the most natural choice for if you’re feeling tired.

Biraz means a little or a bit.

Here it modifies dinlenmelisin:

• biraz dinlenmelisin = you should rest a little / a bit

In Turkish, adverbs like biraz usually come before the verb, so this word order is very natural.

Dinlenmelisin comes from:

• dinlen- = rest
• -meli = should / must
• -sin = you

So it means:

• you should rest
• sometimes you must rest, depending on context

In this sentence, it sounds like advice, so you should rest is the best interpretation.

The Turkish suffix -meli / -malı expresses necessity, obligation, or strong advice.

Depending on context, it can mean:

• should
• ought to
• must

In a sentence like this one, it is usually advice:

• Kendini yorgun hissediyorsan, biraz dinlenmelisin.
• If you feel tired, you should rest a little.

So the exact strength depends on tone and situation.

Because Turkish often leaves subject pronouns out when the verb ending already shows who the subject is.

Here:

• hissediyorsan already means if you feel
• dinlenmelisin already means you should rest

So adding sen is usually unnecessary. Turkish is a pro-drop language, which means subject pronouns are often omitted.

It can change.

The sentence as given:

• Kendini yorgun hissediyorsan, biraz dinlenmelisin.

is very natural and straightforward: if-clause first, main clause second.

But Turkish allows flexibility, so you could also say:

• Biraz dinlenmelisin, kendini yorgun hissediyorsan.

That can sound a bit more like You should rest a little, if you’re feeling tired.

So the original word order is the most neutral, but it is not the only possible one.

Because dinlenmek is the normal Turkish verb for to rest.

It is an intransitive/reflexive-style verb meaning to rest oneself or simply to rest. Turkish commonly uses this verb on its own:

• Biraz dinlen. = Rest a little.
• Dinlenmelisin. = You should rest.

So this is just the standard way to express the idea.

Yes. A more literal version would be:

• If you are feeling yourself tired, you should rest a little.

But that sounds unnatural in English. So the natural English translation is:

• If you feel tired, you should rest a little.

This is a good example of how Turkish and English express the same idea with slightly different structures.