It reviews your whole history
The application asks about arrests even where charges were dropped, about taxes, about time spent outside the country, about selective service registration, and about every prior immigration filing. Anything that does not match an earlier application gets noticed. Most cases are straightforward. The ones that are not are far better identified before filing.
Absences and continuous residence
Long or frequent trips abroad can interrupt continuous residence, and certain absences carry a presumption that residence was broken. If you have travelled a lot, review the history before filing rather than explaining it at an interview.
Good moral character is a defined period
It is assessed over a statutory period, though conduct outside that window can still be considered. Old criminal matters, unpaid taxes, and failure to support dependants are the issues that most often come up.
The tests, and the exemptions
There is an English requirement and a civics test. Exemptions and accommodations exist based on age and time as a resident, and for applicants with a qualifying medical disability.
