It’s Election Day in the nation’s capital and the reason most of us live here can be traced back, one way or another, to voting. But casting a ballot in the District of Columbia is far less universal. The city’s current mayor, Vincent C. Gray (D), won in a landslide four years ago with about 72,000 votes – 12 percent of the population. If predictions of poor turnout prove true Tuesday, he or one of his competitors could win with roughly half that. So, if you’ve never voted in D.C. and don’t know where to start, here’s a primer. P.S.: Don’t feel too bad. You’re not alone. The city has added more than 80,000 new registered voters since the last mayor’s race.

1. Can I vote?

Short answer: Yes. If you have never voted in D.C., the city allows same-day registration. (millennials, you can change it back to Ohio or Michigan by November, if you want). Bring a government ID or a utility bill, bank statement, paycheck or just about anything else semi-official to your polling place, which you can find here. If you’re using your phone, D.C. has an app here.

If you think you might have registered, but can’t remember, check here. About the only thing you can’t do last-minute to vote in today’s Democratic Primary is change your party registration. The deadline for that was a couple weeks ago. More questions? Click here.

2. What if I’m just in D.C. going to college?

Unless you’re a genius and skipped a couple grades, you can probably vote even as a freshman. To vote in D.C.’s primary, you have to be 17 years old — with an 18th birthday coming before the General Election on Nov. 4.

3. What is a “delegate” to the U.S. House of Representatives and a “shadow” U.S. senator?

If you have ever voted anywhere, you’ve probably voted for a real, live member of Congress. A couple of the first races you’ll encounter on today’s ballot my throw you for a loop.

It’s a sore subject, but D.C. residents do not have voting representation in Congress. But you can vote for a non-voting delegate to the House; Eleanor Holmes Norton has held the post for more than 20 years. There’s a more competitive race going on for “shadow” senator, a position dedicated to advocating for statehood.

4. What about that mayor’s race?

With luck, you’ve heard there’s one going on. Gray is seeking a second term. Seven challengers, including four council members, want his job. There's been scandal and a lot of money spent. Read our profiles of the candidates and check out their positions on issues.

5. Who are all the rest of these people on the ballot?

Some are council members. Most incumbents are reassured victory but there are competitive races in Ward 1 and Ward 6. If you don’t know which ward you live in, check here.

There’s also an “at-large” race, which is a council member elected citywide, you can vote for that. And read about it here.

Ya, but what about the other 40 people, the Democratic party this and party that? That confuses even the people who live here. The easiest solution is to vote a slate. Read about them here.