Transitional expressions bridge the gaps between ideas or concepts. The most popular one I know of is: "As a matter of fact". For a list of other useful transitional expressions please see: http://iws.ccccd.edu/WriteStuff/transition.html The use of transitional expression in writing help the reader understand the ideas we are trying to communicate. An overuse of transitional expressions can
. confuse the reader though. These expressions are to be used with caution and a clear understanding of what they mean.