Questions in a lesson are practice, so a wrong answer never counts against your certificate. Get one wrong and you'll see why, with a hint and a second go; miss it again and we show you the answer so you can carry on.
Answering a question
Read the question (1).
Pick your answer (2), or type it, match it or sort it, depending on the question.
Press Check (3). You find out straight away.

- Number 1: The question.
- Number 2: Pick an answer.
- Number 3: Check marks it straight away.
Typed answers aren't fussy about capitals, punctuation or a stray "the" at the start. Spelling still counts, so give it a quick look before you press Check.
If your first answer is wrong
You'll see Not quite (1), with a line on why that answer doesn't work. It won't give the right one away.
Press Get a hint (2) if you'd like a nudge in the right direction. Press Try again (3) to clear your answer and start fresh, or simply pick a different answer and press Check.

- Number 1: Not quite: why that answer is wrong, without giving the right one away.
- Number 2: Get a hint, if you want a nudge.
- Number 3: Try again, or just pick another answer.
If you miss it twice
After a second wrong answer the bar reads Here's the answer, with the right answer and the reason it's right. Press Got it and carry on.
That's the whole penalty: no lockout and no starting the lesson again. We bring the topic back a little sooner in your reviews, so it sticks next time.
When you get it right
You'll see Correct with a short explanation. Where there's more to say, Why? opens the longer version. Press Continue to move on.

How XP works
XP is a record of effort. It's just for you, and it doesn't decide your certificate.
10 XP for a right answer first time, and 5 XP for a right answer on your second go.
5 XP for an estimate or a poll.
20 XP for finishing a lesson, plus 25 XP more if it had questions and you got through them with no wrong answers and no hints.
50 XP the first time you pass a checkpoint.
XP is paid once per question, so redoing a lesson won't earn it again. The practice still counts towards your reviews.