Mark Berelekhis Aug 16, 2009:

Yes, in many cases it is a matter of taste And then I tend to go with my ear.

Mikhail Korolev Aug 16, 2009:

Mark, I'm glad to have heard your opinion.

Well, I'm not sure but it seems to me that using "of" after "half" is, in some cases, a matter of taste, so to speak.

http://dictionary.cambridge.org/define.asp?key=35287&dict=CA...
Roughly half (of) the class are Spanish and the others are a mixture of nationalities

http://www.ldoceonline.com/dictionary/half_1
Over half of the children live in one-parent families.
Only half the guests had arrived by seven o'clock.

Mark Berelekhis Aug 16, 2009:

I think so It sounds off without 'of' (no pun intended). Probably because we're talking about a specific wall.

Mikhail Korolev Aug 14, 2009:

Well, I have to admit I have a question on my own:

Is "of" obligatory in "half of a/the wall"?

http://www.chad.co.uk/ashfieldnews/Caretaker-wants-council-h...
...they have knocked half a wall down and are ripping graves apart