Monica, Regrettably the precise answer is, "it depends on the details": what is the source (location of the property/bank/etc) & the precise category (dividends, salary, capital gains, etc) of income, and what is the nationality & residence of the recipient(s).

The easiest way to tackle this is to make a chart (easy in a spreadsheet), with three columns: his income, your income, joint income, and as many rows as needed for category/source, e.g.
dividends (CH); dividends (US); dividends (other)
bank interest (CH bank); bank interest (US bank)
etc

Given the US-CH tax treaty provisions, whether you are entitled to a deduction or a tax credit for CH taxes (and whether you owe CH or US taxes at all), will depend on which "box" the income falls into and of course the nationality+residence of the recipient.

That is simpler than it sounds.

Are you sure you want to tackle this on your own? A US accountant (CPA) familiar with the tax treaties is not hard to find, and not too expensive.