敬爱的8老师：
在中国大陆出生的美国公民21岁未婚子女，目前该子女已在美国境内；I-130已批准，该何时递交I-485？
-Caculate the child's CSPA age to see whether the child's CSPA age is < 21. If yes, the child can file I-485 now.
The child's CSPA age = the child's current age - I-130 pending dates
Note: I-130 pending dates = I-130 approval date (i.e. I-130 approval notice date) - I-130 receipt date
You can find the I-130 receipt date and the approval date from the I-130 Approval Notice (i.e. I-797).
届时移民局是否会通知我们？
-No. You need to check the Visa Bulletin every month to see whether the PD is current:
https://travel.state.gov/content/visas/en/law-and-policy/bulletin.html
如果在此日期前提前递交了I485表，待到日期到时我们是否还要重新递交？
-If teh child's CSPA age is < 21, the child can not file I-485 until the priority date (PD) is current (i.e. PD is earlier than A. FINAL ACTION DATES FOR FAMILY-SPONSORED PREFERENCE CASES.
Also, the child needs to keep his/her legal non-immigrant status (e.g. H-1, etc.) until filing I-485, i.e. the child can not illegally stay before filing I-485 even if the unlawyful presence is only one date.
F-1等候排期如何计算？
是否是从递交I-130表那天开始？-Yes. The I-130 receipt date is the priority date (排期).
