Well this time the primary difference is that you will also have to write down what you say and what the examiner says
The examiner will also write down what you say
So make sure you speak slowly
Say and write at the same time .By writing down the answer first and then saying it you will lose precious time
You dont have to write down the whole word . You can use abbreviations as well to save time
Here are some recommended ones . But its not compulsory to use the same
http://www.wpc.dot.gov.in/DocFiles/abreviations.pdf
In the end the someone checks both answer sheets and marks accordingly