@pk12_2 Thanks so much for the explanation. I really appreciate that. The example you given has made me much more clear about what to file now.
But let me ask a question about the foreign income exclusion.
In your point(b)(i), about the requirement for qualifying HK as the foreign tax home for excluding the foreign income in 2021, does it mean she has to stay in HK for at least 330 days in the 12 month period (11/29/2021 - 11/28/2022)? But it involves a future time at this moment. So if my wife eventually stays in HK for less than 330 days in this period, will the exclusion become invalid?
@leo_oel
about whether for purposes of being able to exclude the foreign earnings from US taxes , she would need to be abroad for 330 days in a test period of continuous 365 days --- that establishes the tax home. If she comes back to the USA early, then the whole effort is lost . Then the only option available to reduce the bite of double taxation is to use the foreign taxes paid as a credit against the US taxes to be levied ( usually not 100% because it is based on a ratio of the filer's foreign income to world income-- so US income reduces the ratio and therefore the credit available for the year ) or as a deduction if one itemizes ( but then there is a SALT - Sate and local Taxes limit). I have known of a lot of people , when I was an expat, that will finish their foreign assignment and stay an extra few days in Canada or somewhere abroad just to satisfy the 330 days abroad clause to meet the Physical presence test.
We are talking about future , only because while the foreign tax credit for 2021 may not be much , if indeed she plans to stay for the whole of 2022, then you could possibly exclude most if not all of her foreign income from US taxes -- and yes it is future. As I said , how you proceed depends on your longer term plans -- where you work , where you each stay etc. etc.
Hope that clears the up things
pk