How to write a test condition and test case

Here are few steps in creating test conditions and test cases:

1. Try to know or understand more about the particular functionality of the software/system by various means. This can be done by reading up on the specifications document and/or user guide, talking to subject matter experts or even playing around with the system.
2. Once you have become more familiar with the to-be-tested functionalities of the system, then it is time to identify all the test conditions. This can be thought of as an aim or goal of the test cases.
3. Once those test conditions have been identified, you need to now create test cases to test those test conditions. This would involve the following activities:
   1) Identifying any necessary test data
   2) Identifying series of steps the tester needs to perform testing
   3) Identifying expected results