I was reassessed for year 2002 income tax. Somehow I forgot to claim one T4A which was for the Ontario student opportunity grant part (about $300). I must have believed it was exempted then coz I wrote something tax-free on that T4A. Anyway, now the CRA sent me a letter asking for the payment for the income tax for that part so I wrote them a cheque.
I believe you need to report to them if you are sent a T4A. If you haven't got the T4A,check with national student loan centre. But I believe the first $3,000 (for scholarship) or $500 (for grant) is tax free. Don't quote me, check CRA's website first.