This article proves statistically the effectiveness of humour in the teaching of English and German to Spanish students of foreign languages. The referred lexicon is particularly troublemaking because of the difficulties that such vocabulary poses for Spanish learners of not-Latin-originated languages. The approach followed is a quantitative and contrastive analysis and was carried out with four groups of Spanish learners. The experimental groups (one for each language) were presented with the input they were supposed to learn in sentences and contexts in which the use of the English/German term, with the meaning of its Spanish 'false friend', resulted in nonsensical and highly humorous utterances. The presentation of the same lexical items to the control groups was more neutral and deliberately bereft of humour. After that, the participants were set a test to find out whether or not they remembered the proper sense of the lexicon taught and could also use it correctly. The results are conclusive and the outcome strongly supports the beneficial effects of pedagogical humour in the language classroom.