Four countries, four quite different tests. Pick yours to see how it works and try free practice questions.
Every one of these tests comes from an official study guide. If a fact is in the guide, it can be on the test. If it isn’t, it won’t be.
That makes them very learnable. Read the guide once, then practise until the answers feel boring. That’s usually the point you’re ready.
In most cases, yes, if you’re an adult applying to become a citizen. Each country has exceptions, often for age or health. Check the official site for your country before you book.
No. Questions are drawn from a larger bank, so two people rarely get the same set. That’s why it pays to learn the guide rather than memorise answers.