Quick answers about the Illinois knowledge test.

Illinois sets the written exam at a minimum of 35 questions, and you have to answer 80 percent of them correctly. On a 35-question exam that's 28 right. The figure lives in the Secretary of State's own rule, 92 Ill. Adm. Code 1030.80(b), not in the manual: Rules of the Road describes what the exam covers and never prints a question count or a pass mark anywhere. Read 35 as a floor rather than a length, because the rule says minimum. The exam asks you to identify traffic signs by shape, color or symbol, identify signals and pavement markings, and answer multiple-choice and true-or-false questions on traffic laws, safety rules, crash prevention and vehicle equipment.

Eighty percent. On the 35-question minimum that's 28 correct and 7 misses, and the rule that sets the standard is 92 Ill. Adm. Code 1030.80(b). There are no scored sections, so one overall total decides the result and no single area can sink you on its own. Illinois publishes no time limit for the written exam either, so read each question all the way through before you pick. One caution about the miss count: 80 percent is the fixed number, 35 questions is only the floor, so a longer exam gives you more misses and not fewer. Plan against the percentage.

Yes, and it usually costs you nothing. Your application fee covers three attempts at each exam within one year from the date you paid it, so a second sitting is a matter of time rather than money. The testing rule also allows a second attempt the same day during normal business hours, though a third road-test attempt in one day is not allowed and the examiner can refuse a same-day retry if your first road test was unsafe. The waiting periods you may have read about, 30 days and 90 days, apply to commercial permits and licenses, not to a Class D applicant. One thing does lock you out: anyone caught cheating fails the exam and cannot retake it for 30 days.

An original Class D instruction permit is $20. The license itself is $5 for ages 18 to 20 and $30 for ages 21 to 68, and a state ID card is $20 for ages 18 to 64. Neither the written exam nor the driving exam carries a separate fee, so the application fee you already paid covers your attempts. There's a quiet saving worth knowing about: if you get your license before your instruction permit expires, you may not have to pay anything more, and the permit is valid for up to two years. Fees are subject to legislative change, so check the current figures before you go.

You have to prove three things at the DMV: who you are, your full Social Security number, and where you live in Illinois. Identity can be a U.S. birth certificate, a U.S. passport or passport card, a permanent resident card, a foreign passport with an approved I-94, a naturalization or citizenship certificate, or a Consular Report of Birth Abroad. The Social Security number can come from the card itself, an SSA-1099, a W-2, or a pay stub showing your name and full number. Residency comes from documents such as a utility bill or bank statement issued within 90 days, a lease or deed, a recent pay stub, or official government mail. A REAL ID needs two current residency documents; a standard license needs one. Photocopies are not accepted. If your identity document carries a different name from the one you use now, bring certified linking paperwork, and note that Illinois wants a marriage certificate issued by the County Clerk rather than a church certificate.

Fifty hours, and 10 of them have to be at night. That's on top of driver education, not instead of it, and it applies to every driver under 18. The supervising adult has to be a parent, legal guardian or responsible adult who is at least 21, holds a valid license, has at least a year of driving experience, and sits in the front passenger seat next to you. You also have to hold the instruction permit for a minimum of nine months and stay free of driving infractions, underage alcohol convictions and court supervisions across that whole period, which means a ticket restarts your clock rather than just costing you a fine. Track the hours on the state's driving log and bring it signed when you apply, because the DMV asks for it at the counter.

Nighttime driving is off limits from 10 p.m. to 6 a.m. Sunday through Thursday, and from 11 p.m. to 6 a.m. on Friday and Saturday. That applies through both the permit phase and the initial licensing phase, and your local curfew may start earlier, in which case the stricter one wins. Passengers are capped separately. For the first 12 months you're licensed, or until you turn 18, whichever comes first, you may carry only one passenger under age 20, and siblings, stepsiblings, children and stepchildren don't count against that limit. After that the cap loosens to one passenger in the front seat plus the number of safety belts in the back. A traffic conviction during the initial licensing phase can push these restrictions past your 18th birthday.

Zero. Illinois runs zero tolerance for anyone under 21, so any trace of alcohol in your system while driving suspends your driving privileges for a minimum of three months, with no impairment and no 0.08 reading needed. A DUI conviction under 21 is heavier still: revocation for a minimum of two years on a first conviction. The 0.08 limit you've heard about is the adult threshold, and commercial drivers sit at 0.04. The number that catches under-21 drivers on the exam is the one that isn't a number at all, so answer this one as zero rather than reaching for 0.08.

Twenty miles per hour, but only when three conditions line up: it's a school day, children are present, and the zone is signed. The school day for the speed limit runs from 6:30 a.m. to 4 p.m. Outside those conditions the normal posted limit applies. Here's the detail the exam can catch you on. Illinois defines a school day twice, with different hours. The 20 mph speed zone starts at 6:30 a.m., while the duty to stop for a pedestrian at a school-zone crosswalk starts at 7 a.m. Both run to 4 p.m., both need posted signs and children present, and the two rules sit in adjacent sections of the Vehicle Code. Fines for the crosswalk violation start at $150 and rise to $300 for a repeat.

When you approach a stopped emergency vehicle with its lights flashing, change into a lane that isn't next to it, as long as the road has at least four lanes with two going your way and the move is safe. If you can't change lanes, slow down, proceed with caution, be ready to stop, and leave a safe distance until you're past. The same duty applies to a disabled vehicle with its hazard lights on. The reach of this law is wider than most drivers assume, because it covers any vehicle authorized to display those lights: tow trucks, highway maintenance and construction vehicles, survey crews, utility and automotive service vehicles, and snow-removal equipment, not just police, fire and ambulance. Penalties are steep, from $250 to $10,000 for a first violation, with a suspension of 90 days to two years where someone is hurt. Illinois also prohibits photography and cellphone use within 500 feet of an emergency scene.

Stop for a school bus whenever its red lights are flashing and the stop arm is out, from either direction, and stay stopped until the arm folds back in and the lights go off. Illinois gives you one exception, and it turns on lane count rather than on a median: on a road with four or more lanes carrying traffic in both directions, you don't have to stop for a bus in the opposing roadway. A plain four-lane street with nothing but paint down the middle counts. That's worth pinning down, because Indiana next door writes the exception the other way and requires a physical barrier. You always stop on any two-lane road, rural or in town, and in a parking lot on school property. The amber flashers come on 100 feet ahead of the stop, 200 feet in rural areas, so treat those as your cue to slow. A conviction carries a $300 fine and a three-month suspension, rising to a year for a second offense within five years.

Illinois bans handheld cellphone use, texting and other electronic messaging behind the wheel. Hands-free and Bluetooth are allowed, but only for drivers age 19 and older. Under 19, every kind of cellphone use is off limits, hands-free included, unless you're calling law enforcement, a health care provider or emergency services. Holding the phone on speaker doesn't make it hands-free, and it's still a violation. So are watching or streaming video, joining a video call, and opening a social media app while driving. Headsets are banned as well, though a single-sided earpiece is fine. You may use a handheld phone only to report an emergency, while parked on the shoulder, or while stopped in obstructed traffic with the vehicle in neutral or park. Fines run $75 for a first offense, then $100, $125 and $150.