"I don't think that that can be done" [duplicate]

Possible Duplicate:
How do you handle “that that”? The double “that” problem

Is there something wrong with this sentence?

"I don't think that that can be done."

It sounds odd to me. Would it be better if I'd use just one "that" instead of two:

"I don't think that can be done."

Solution 1:

Both are correct, but the second is preferred.

In option 1, the first that serves as a conjunction introducing the subordinate clause "that can be done," which is the object of the verb think. The second that is simply a pronoun substituting for the subject of the subordinate clause.

Option 2 is better because (1) it avoids the awkwardness of the double that and (2) the sentence is still perfectly intelligible without the conjunctive that.

That is quite a flexible word. :)

Solution 2:

In that sentence, that can be omitted, similarly to what is done in the following sentences.

He will understand I was not joking.
Several people read the question you wrote.
I am sure you will be able to resolve the issue.

I would write the sentence avoiding to write that twice, but that doesn't mean it is wrong to write "that that."