Why i can't use my sim card at my iphone 4?

My dad bought me an iphone 4 from us and when he came back here in philippines i found that it can't use local sim card.anyone can explain this?

Because iPhone requires a nano sim
Local sims are micro sims
So buy one
I personally never recommend apple for these kind of issues

Because you have normal sim cut the sim to micro sim avalible some dive to cut.

From what you are telling it seems like you have a phone that is locked to a carrier in the US. You will need to unlock it before you can use it Philippines. Also MicroSIM is used in iPhone 4