This paper addresses the question of the learnability of generalized quantifiers. This topic was first taken up in (van Benthem 1986a) but has received little attention since then. There are a few results: in (Clark 1996) it was shown that first-order generalized quantifiers are learnable with membership queries. In (Tiede 1999) it was shown, among other things, that the left upward monotone quantifiers are learnable from positive data. Applying results from the field of formal learning theory the results from (Tiede 1999) will be strengthened: it is shown that these classes are learnable under psychologically plausible restrictions on the learner.