We expect that every patch will have impact on the _English.csv file (corrections, additions, may be removals of strings), so it is a good idea to be prepared for the next patch. To search for the changes I'd suggest using diff tools (you can google for them, they open original file in left and new file in right and show differences between two text files). To use them and see the differences you need to have the original (previous version) _English.csv file, so it is a good idea to have a copy.
Example diff tool output:
Just FYI.