Possible Duplicate:
How do you handle “that that”? The double “that” problem
I've encountered this sentence in a technical book:
A browsing context has a session history, which lists the Document objects that that browsing context has presented.
What is the grammaticall role of each "that" here? Can we consider using two consecutive "that" as a poor writing style from the point of user understanding?
The first "that" means the same as the word "which" in this context, and so can easily be replaced with it as such:
A browsing context has a session history, which lists the Document objects which that browsing context has presented.
The second "that" refers to the "browsing context".
I use "that" twice consecutively on occasion, but I will often try to rephrase the sentence to do away with that potentially awkward construct. For example, I can rewrite your given sentence as:
A browsing context has a session history, which lists the Document objects presented by that browsing context.
