I have just arrived in Riga for ESSLLI 2019. Tomorrow, Shane and I start teaching the class on the learnability of quantifiers. Only a very limited subset of the mathematically possible quantifier meanings are expressed in any natural language. One would like an explanation of this fact: why do we only find particular kinds of quantifiers in all languages? This course will assess the idea that the quantifiers we find in natural language are the ones that are easier to learn.