3 years in the previous 4 that you have to have lived in Canada after becoming PR but if you are already here on a work permit, you may count that time at 50% value. For example, if you are here 18 months before you become PR, you can count this as 9 months towards the 3 years and then it would be 2 years and 3 months you have to stay in Canada as PR before you can apply for citizenship. If you take any vacations outside Canada during this time, you have to add that to the time you have to stay.
