olduğunu - that is

Hello! Starting from today, I will publish the lessons and the vocabulary items on our new interface (http://www.learnturkisheasy.com) as I thought that it will be more organized and the menu will be easier to use for you. But we continue to learn the most common Turkish words on this page. As this page is first    yours, of course I am open for your ideas, too. 

Today's word is "olduğunu". It is the 39th most common word in Turkish Language. This word has no meaning when it is alone. Let's see how it works.

First, please have a look at this sentence and try to guess how to say it in Turkish.

"I know that this is wrong"

The most simple way is that;

Bu yanlış, biliyorum. This is wrong, I know (it).

The second possible way is that;

Biliyorum ki bu yanlış.

But if you've read the article about "ki" , you already know that this is not so common way that we use. 

Now I'm writing the third and the most accurate Turkish translation of this sentence;

Bunun yanlış olduğunu biliyorum. "I know that this is wrong"

You are free to use one of these three options, but just know that the third way is not only the most accurate but also the most common one. It can seem complicated if you've just started to learn Turkish. But like always I do, I will try to simplify it. And to do this I will use other examples.

Onun güzel olduğunu biliyorum. I know that she is beautiful.

Sorunun doğru olduğunu söyledi. He said that the question is accurate.

Yanlış olduğunu kabul etti. He admitted that he was wrong.

Arkadaşının doktor olduğunu neden söylemedin? Why havent you told me that your friend was a doctor?

Bana okulda olduğunu söyledi. He said that he was at the school.

There is one thing common in all these sentences. If we look from the English side, we see a sentence after the word that, and that sentence describes something or someone, with a noun or an adjective. I underlined those sentences. These are just normal sentences with the verb "to be" (which is "olmak" in Turkish). So, this is not different with such a sentence;

I know this. --> What do you know? --> She is beautiful.

So, when we need to use these "to be sentences" in other sentences, in other words when they play a noun/object role in other sentences, the verb olmak comes to our help in the form of "olduğunu".