Many of the rejection reasons are straight forward; however some reasons are not so simple. Some examples of such reasons are:
You have not satisfied me that you will leave Canada by the end of the period authorized for your stay because:

• You have not demonstrated that you are sufficiently well established in your country of residence.
• Your proposed studies are not reasonable in light of one or more of the following : your qualifications, previous studies, employment, level of establishment, other educational opportunities available in India (the country of the applicant) or Canada, language abilities, or your future prospects and plans.
• You have not satisfied me with regulation 179 that you would leave Canada at the end of the temporary period.
• You have submitted documentations which lacks credibility as part of your application. This has diminished the overall credibility of your submission.
• You have not provided documents that demonstrate the relationship between you and your sponsor (other than your parents).
• You have not demonstrated that your sponsor will provide adequate support to cover the cost of your studies.
• You have failed to comply with our request for an interview. Based on the information provided, you have not satisfied me that you meet the requirements for issuance of a study permit.