How do you get a heart?
I frequently want to get a heart near the end of a lesson, but when I try to buy one, the program throws me back to the beginning. Then it tells me that I should have bought a house. What's with that?
Buy a refill before starting a lesson. If it wasn't needed, no problem! You can use the refill in another lesson. It's useless to buy refills during a lesson, as the lesson ends directly if you go to the store.