I have studied in Singapore before. Will this give me an advantage when applying for PR?
It all depends on where you studied. If you went to a local school (NUS, SMU, NTU, TP, NP, NYP, RP, SP, etc.), you will have an edge over other applicants, as the ICA officials will take it to mean that you were able to successfully integrate with the local community. Having attended international schools or private institutes will not be as advantageous.