There is a free Form Maker but it does not do short answer questions. This is far more comprehensive and supported but not free. It is, I think, 30USD a year for individuals and 99 USD a year for a school. 30 USD is quite a lot to me bearing in mind that I generally use Moodle for quizzes so I think I will only be using it today. No. It seems that there is no way of setting the correct answer for short answer questions (the correct answer is instead added to feedback). I am not sure if this is a limitation of google forms quizzes but since an automated way of setting up short answer questions with answers is what I want, I don't think that this is for me.