dual citizenship

Not automatically. He acquires citizenship on his tenth birthday, or earlier if you become a citizen first. Australia allows dual citizenship, so you wouldn’t have to renounce it. Citizenship takes effect at a ceremony.

不是自动的。他会在十岁生日当天自动取得国籍；如果您先入籍，则会更早。澳洲允许双重国籍，所以您不必放弃原国籍。国籍要在宣誓仪式上才正式生效。