Though policies vary state-to-state, the Department of Motor Vehicles in Connecticut allows individuals to take the learner's permit test in a number of languages, including Portuguese. Driver's manuals are also available in Portuguese.
DMV.org provides various information for soon-to-be drivers, including how to apply for a license, register a vehicle and pay traffic tickets. It also provides some information on the language regulations for each state's DMV tests. Type Language into the search bar at the top of the page, select a state, click Go and review the links below. Many states at least administer the tests in Spanish and English.