it is used on spoken and written langugae, but mostly preferred in spoken language.

One more example:

Ne diye bağırıyorsun bana şimdi? why are you yelling at me now?

Ne diye? =Neden?

We can use ¨diye¨with different meanings

PS: Sorry about my English

 I am a learner ... so as one learner to another ... the best English equvalent [to me] seems ´Diye´ > with the intention of> intending to > indicating that > implying > meaning that [from Demek]>

For example, upon her mother´s demise, a friend wrote to me:-

1)  ´Simdi annem uzun bir uymakte durumda diye dusuniyorum´ > ´I intend to think that my mother is in a state of a deep slumber´ ... or something like it. 

2)  ´Ne yapiyorsun´ diye sormuş. > He intended to ask, ´What are you doing´

3) Eglenecegim diye sinimaya giyorum´ > ´I am going to cinema with the intention that I will enjoy myself´

Mostly it is used for reporting what someone ´said´ ... and may be, the intention of the speaker

I hope this helps you.

Tazx1

I think No.2 just translates as ´he asked´ not ´he intended to ask´ - as far as I´ve been taught anyway. If it had been ´Ne yapiyorsun´ diye bağırdı´ it would translate as ´what are you doing?´ he shouted.

One more question: can you speak turkish without using this odd diye?

 Ahh thats a good explanation,

These lyrics from Candan Erçetin - Mühim değil, make more sense to me now:

Bazen de gülümsedim nazikçe

Dinlemegiğim belli olmasın diye

Sometimes I smiled politely

So that/in order that (the intention was) it wasnt obvious I didn´t listen

So thanks for the explanation

Maybe this excerpt from Lewis´ "Turkish Grammar" (p. 175) will be useful:

(it´s a screenshot from the version published under the link above, I hope I´m not doing anything wrong pasting it here)

"diye" comes from "demek" and it has got a lot of meanings:

1) Used for "called" meaning; describing noun:

Bunu bana Ahmet diye birisi söyledi.

Someone called Ahmet told me this.

Yenimahalle diye bir yerde oturuyor.

He lives in a place called Yenimahalle.

2) Describes action (except ´said´ in Direct Speech:

"I didn´t do that!" he shouted.

"Bunu ben yapmadım!" diye bağırdı.

"Buraya gel." dedi.

"Come here." he said.

"Where is your home?" he asked.

"Evin nerede?" diye sordu.

3) Used as "because of" :

Sınav var diye dışarı çıkamıyorum.

I can´t get out because of there is exam.

Zamanı yetmedi diye soruları cevaplamadı.

He didn´t answer questions because of his time was unsufficient.

4) Connects little Direct Speeches with sentences.

Seni oraya gitme diye uyardım:

I warned you as ´don´t go there´.

Yapma diye defalarca söyledim:

I told him ´don´t do´ for several times.

thx

turkishcobra //