It’s pretty easy to understand. It depends on a few different things - you can be born to a US mother and not be a citizen, or to a US father and get citizenship through him. It depends on marriage status and there are different residency requirements for different situations. Those requirements are different depending on which parent is the US citizen too.
Here’s the law if you’re interested in learning about it: https://www.uscis.gov/policy-manual/volume-12-part-h-chapter-3
It’s pretty easy to understand. It depends on a few different things - you can be born to a US mother and not be a citizen, or to a US father and get citizenship through him. It depends on marriage status and there are different residency requirements for different situations. Those requirements are different depending on which parent is the US citizen too.