Konuşma dönüşmek istiyorsa, sen de biraz özen göstermelisin.

Here konuşma is a noun, meaning something like conversation, speech, or talking, depending on context.

It comes from the verb konuşmak (to speak / to talk) plus -ma, which can create a verbal noun.

So in this sentence, konuşma is not don’t speak. It is the subject of the first clause.

• konuşmak = to speak
• konuşma = speaking / conversation / speech

A learner may confuse this with the negative imperative, but here it clearly functions as a noun.

Because Turkish often uses the infinitive before istemek (to want).

So:

• dönüşmek = to transform / to turn into / to evolve
• dönüşmek istiyor = wants to transform / wants to turn into

This is similar to English want to do.

So the structure is:

• konuşma dönüşmek istiyorsa
  = if the conversation wants to transform / evolve

Even if the exact English translation is smoother in context, grammatically this is infinitive + istemek.

İstiyorsa can be broken down like this:

• iste- = want
• -iyor = present continuous / non-past stem
• -sa = conditional if

So:

• istiyor = wants / is wanting
• istiyorsa = if (he/she/it) wants

In this sentence, it refers to konuşma, which is third person singular, so there is no extra personal ending after -sa.

The subject is konuşma.

So the first clause is structured like this:

• Konuşma = the conversation
• dönüşmek istiyorsa = if it wants to transform / evolve

Turkish does not need a separate word for it here, because the subject noun is already present.

So you do not need something like o.

It is understandable, but many learners would notice that it sounds a bit personified or slightly unusual, because konuşma is being treated as if it can want something.

A more natural Turkish sentence in many contexts might be something like:

• Konuşmanın dönüşmesini istiyorsan, sen de biraz özen göstermelisin.
  = If you want the conversation to evolve/change, you should also make some effort.

So the given sentence is grammatically analyzable, but stylistically it may feel less natural than some alternatives.

Sen de means you too, you also, or you as well.

• sen = you
• de = also / too

So it adds the idea that you are also responsible, not just the other side.

This often carries a nuance like:

• you should do your part too
• you, too, need to make some effort

Because this de is the particle meaning also / too, and that is written separately in Turkish.

So:

• sen de = you too

This is different from the suffix -de / -da meaning in / at / on, which is written attached:

• evde = at home
• okulda = at school

A common learner question is whether this is the same de. It is not.

Özen göstermek is a common Turkish expression meaning:

• to take care
• to be careful
• to show care
• to make an effort
• to pay attention

Literally, it looks like to show care, but in natural English it often means something like to put in care/effort.

So:

• biraz özen göstermelisin
  means something like
  you should make a bit of effort
  or
  you should be a little more careful / attentive

Göstermelisin breaks down as:

• göster- = show
• -meli = should / must
• -sin = you (second person singular)

So:

• göstermelisin = you should show

In the full expression:

• özen göstermelisin = you should show care / you should take care / you should make an effort

A very common learner confusion is thinking -me here is negative. It is not negative in this word. The form is:

• -malı / -meli = necessity suffix

So göstermelisin means you should show, not you should not show.

Biraz means a little, somewhat, or a bit.

Here it softens the sentence and makes it sound less harsh.

Compare:

• özen göstermelisin = you should make an effort
• biraz özen göstermelisin = you should make a bit of effort / you should be a little more careful

So biraz often makes advice sound more natural and less blunt.

Turkish very often puts the if-clause before the main clause.

So this order is very natural:

• Konuşma dönüşmek istiyorsa, sen de biraz özen göstermelisin.

That is:

• If ..., then ...

The comma is also normal here.

Turkish word order is flexible, but putting the condition first is the most straightforward and common arrangement.

Turkish often does not need an explicit word for then after an if clause.

The meaning is understood from the conditional suffix -sa / -se.

So:

• istiyorsa already sets up the condition: if it wants...
• göstermelisin gives the result/advice: you should...

English sometimes uses then, but Turkish usually does not need it.

Yes. Turkish often drops subject pronouns when they are already clear from the verb ending.

So you could say:

• ... biraz özen göstermelisin.

because -sin in göstermelisin already tells us the subject is you.

However, using sen adds emphasis.
Using sen de especially highlights you too.

So the pronoun is not required for grammar, but it is useful for emphasis and contrast.