Hi Ana,
I also vote for the null option :-)
Google Trends can help if you need to check on how often a particular phrase is used.
Mouse over the red lines for the actual numbers.
It �s an interesting question, definitely not a silly one, because it shows how we associate new things with things we already know and apply the relevant �old � prepositions.
"Search in this blog" because a blog is a text and similar to a book or journal, is contained and limited maybe?
"Search on this blog" because a blog is a website? Or is on a computer? (This one would be my least favourite, but I could imagine saying it)
"Search this blog" because a blog is three dimensional? Like a house? Too large to be �contained �?
Does anyone think that these two sentences carry the same meaning and strength:
"Search in this blog for the writer �s recipe for pumpkin soup"
and
"Search this blog for the writer �s recipe for pumpkin soup"
They feel slightly different to me.
Tap