I ran across some examples which helped me to understand what is confusing about Turkish present continuous. It is the way that it refers to both near past (or past with an influence to present) and near future.

         Burada mayıs ayından beri oturuyoruz.

         Ben geliyorum onbeş dakika sonra.

If the latter one was alone I most certainly would have understood that the action was going to take place after fifteen minutes but the context convinced me that the person who said this had already come fifteen minutes ago.

Yesterday someone asked in the Translation section which one is correct: İki gün sonra Antalya´ya geliyorum or geleceğim. The questioner was taught that they are both OK. So, here present continuous refers to the future just like in examples like

         Ay başında sergimiz açılıyor.

In other words, sentences in which exactly the same tense is used can refer to two directions in the time line. Or is there something about them that I didn´t notice?

Thanks, si++. It seems that in both these cases there is something that ties the situation with present moment. What happened is still valid and the basis of what is going to happen has been laid here and now as a plan or decision or intention.

Another problem is that sometimes present continuous is used in cases which in my opinion describe habitual action but just wait until I find the perfect examples (leafing through my books anxiously)...

I think it all depends on a reference point. Usually reference point should be the present time.

Let´s think about something in the past.

I went home yesterday at 2 pm. I changed my clothes and went out at quarter past 2 pm. Now I can tell it to you this way:

"Saat 2´de eve geliyorum. Üstüme değiştirip on beş dakika sonra çıkıyorum."

= "I´m coming come at 2 o´clock, changing my clothes and and leaving 15 minustes later."

So reference point is 2 pm yesterday but I tell it like a present time.

Reference point is the key word. Sure. And that is because as human beings we are tied to this moment and place but our mind is free to move and it´s our mind that language reflects.

What would you say if I found one:

         Her sabah dört saat yazıyorum.

I didn´t invent it.

Hmm. We usually use "simple present (or aorist) tense" for habitual activities.

Her sabah dört saat yazarım = I write for 4 hours every morning.

Her sabah dört saat yazıyorum = (Nowadays) I write for 4 hours every morning.

It gives you the feeling that you are talking about an habitual activity that is being done currently (yesterday, today and probably tomorrow).

The first one is more generic and tells you that you have an habit of writing in general (you may have not written today for example but it is (or may be) still an habitual activity that is taking place 3 days a week for example).

This is not fair, I know. I look for a special case from a book and you have to explain it. We have a saying for this: One dummy can ask more than ten wise men can answer.

Thanks again. (I´m gone.)

Ah we have similar saying:

"Bir deli kuyuya taş atmış kırk akıllı çıkaramamış."

"One madman drops a stone into the well and forty wise men cannot take it out."