özne almayan cümleler de vardı.

Bunlar "geçişsiz fiiler"den "-l-" ve "-n-" eki ile türetilen edilgen çatılı fiilerle kurulan ve "gereklilik kipi"nin üçüncü tekil şahasının genel anlamda kullanılması ile oluşturulan cğmelelerdir.

"saat dokuzda yatıldı"---1

"Çok çalışmalı"---2

I´m so confused...

In the sentence 1 the subject is really unknown but in the sentence 2 the subject is O,isn´t it?

 I am a learner myself [Health Warning].  But accoring to my understanding the prnoun [He/she/it] is indicated in ... the ´-dı´ ... of the phrase ´yatıl-dı´ ... because:-

Yatilidim, yatildin, yatildi,      yatildik, yatildiniz, yatildiler

    I,         thee,  he/she/it,       we,       you all,    they

In my view ... to emphasize one could say > ´O saat dokuzda yatildi´

... and schlars know best !!

Saat dokuzda yat|ıl|di is a passive sentence. To be exact, it represents a Turkish speciality, the impersonal passive which means that some people did, we don´t know or we don´t bother to mention who they were. There is no subject in the sentence.

There is a real, English type passive in Turkish also. In real passive sentences the object of the action is risen as the grammatical subject of the sentence.

lovelovevampire, you suggest that in Çok çalışmalı the subject would be a dropped o. Sure the sentence could be translated this way. But as it is brought up here next to the subjectless impersonal sentence maybe the author wants to tell something else. I am a learner myself and I am asking just like you if

                 Çok çalışmalı

could be interpreted as a monopersonal sentence, where the subject is human but unknown just like in sentence nr 1.

It depends on the complete sentence/context..

1) 3rd person singular:

Çok çalışmalı yoksa başarılı olamaz.

2) Subjectless:

Çok çalışmalı ve başarılı olunmalıdır.

Good.

Not only intransitive verbs (geçişsiz fiiller )..

But also transitive verbs (geçişli fiiller ) :

tarla sürüldü, mısır ekildi, inekler sağıldı, vb

Passive transitives take personal endings:

ben işe alındım

sen işten atıldın

o askere alındı

biz buraya gönderildik

siz listeye eklendiniz

onlar avluya çıkarıldılar

Pronouns (zamirler ) in these sentences are not subject (özne ) but object (nesne ).. and personal endings (kişi ekleri ) in the verbs refer the object ( the rule saying "PE in the predicate always tell us the subject" is not valid anymore   .. Some linguists call  the object in this type of sentences a so-called subject (sözde özne )... 

My professor always called the NP of impersonal clauses a ject because there were features from both subject and object in it.