Because my green card allows me to travel between the United States and my home country, can I live in both places until I am ready to apply for citizenship?

To qualify for citizenship, applicants typically must show that they have lived in the United States continuously for at least five years prior to filing Form N-400 (Application for Naturalization).  This means that you must only live in the United States and not any other country.

You may travel to another country, including your home country, provided there are no other legal obstacles preventing you from doing so.  However, if the trip lasts more than 180 days, USCIS may determine that you have not resided continuously in the United States and are therefore ineligible for naturalization.

In addition to examining the length of your travel abroad, USCIS will also examine the frequency of your travel.  To qualify for naturalization, applicants must spend at least half their time in the United States.  This is known as the "physical presence" requirement.  You are also ineligible for naturalization if you take frequent short trips abroad that result in you spending more than half your time outside the United States.

The requirements of "continuous residence" and "physical presence" are interrelated but distinct requirements.  A naturalization applicant must meet each requirement to be eligible for naturalization.