In this task, you will be shown an incorrect English sentence. You need to generate a corrected form of the input sentence.

Example input: The car's wheel are loose.
Example output: The car's wheel is loose.
Example explanation: The instance of are is replaced by the word is. This makes the sentence grammatically correct.
Q: When you understand the concepts and ideas is up to you to prove them , to see if they are really what you have been told , i think this is the main reason why students prefere facts rather than just understanding ideas and concepts . 
A:
When you understand the concepts and ideas it is up to you to prove them , and see if they are really what you have been told ; I think this is the main reason why students prefer facts rather than just understanding ideas and concepts . 