[Grammar] Condtional

[Paulys]

Which one of these words look better in the following sentence? "You will fail the exam unless you start (to study) or (studying)"

 

[bhaisahab]

Which one of these words look better in the following sentence? "You will fail the exam unless you start (to study) or (studying)"

I would say: "You will fail the exam unless you study." or "You will fail the exam unless you start studying (for it)."