Re: Cleft sentences
#1 is, as you know, fine.
Originally Posted by barnej0096
#3, whilst grammatically correct, would not be uttered. It is completely unnatural.
I will make an argument for a version of #2 but not with "It" at the beginning. For this, read the following dialogue:
A - Mary threw a jug out of a window last night!
B - Why?
A - Oh, she was having an argument with her boyfriend.
B - Which window did she throw it out of?
A - The one on the third floor next to where the name of the building is painted.
B - I don't know which one you mean. Can you show me?
A - Yes of course. Come outside with me for a moment.
(The two go outside and A points up at a specific window.)
A - That is the window that she threw the jug out of.
Remember - correct capitalisation, punctuation and spacing make posts much easier to read.