Handwriting can be very difficult to read. Not only do individuals write very differently, people from different countries were taught different writing styles.
The sentence "The quick brown fox jumps over the lazy dog" contains at least one example of each English letter. It is commonly used when someone wants to test that each letter is present and appears correctly.
Fourteen professors wrote the sentence to illustrate variations in handwriting that you may need to decipher. Their writing is displayed below to serve as a kind of Rosetta stone. http://www.ancientegypt.co.uk/writing/rosetta.html
The canonical sentence does not contain common word endings (-ing, -tion) that people tend to write particularly illegibly. When you encounter poor handwriting, be aware that you will need to guess much of the meaning from the context.
And good luck!