[General] how big is it vs how big it is

[murattopak]

I was looking at this
How many words does a native English speaker know? - Yahoo! Answers

"Thank you. Don't worry didn't believe a native English speaker knows only 2000 words.I knew they hold a bigger vocabulary but I wasn't sure how big is it. Usefull information anyway."

Here is my question

Can I say "I wasn't sure how big it is" or is the sentence above true?

 

[emsr2d2]

I was looking at this -
How many words does a native English speaker know? - Yahoo! Answers

"Thank you. Don't worry didn't believe a native English speaker knows only 2000 words.I knew they hold a bigger vocabulary but I wasn't sure how big is it. [strike]Usefull[/strike] Useful information anyway."

Here is my question: Can I say "I wasn't sure how big it is" or is the sentence above [strike]true[/strike] correct?

There are several problems with the quote. In my opinion, it should read:

"Thank you. Don't worry, I didn't believe [that] a native English speaker knows only 2000 words. (space required here) I knew they had/held a bigger vocabulary but I wasn't sure how big."

 

[MikeNewYork]

I was looking at this
How many words does a native English speaker know? - Yahoo! Answers

"Thank you. Don't worry didn't believe a native English speaker knows only 2000 words.I knew they hold a bigger vocabulary but I wasn't sure how big is it. Usefull information anyway."

Here is my question

Can I say "I wasn't sure how big it is" or is the sentence above true?

In that sentence, it should be "how big it is". As a question, it should be "How big is it?"