This study describes the introduction of verbal idioms in the Galician language version (Galnet) of the semantic network WordNet; a network that does not traditionally include many phraseological units. To enhance Galnet, a list of 803 Galician verbal idioms was developed to then review each of them individually and assess whether they could be introduced in an existing WordNet synset (a group of synonyms expressing the same concept) or not. Of those 803 idioms, 490 (61%) could be included in this network. Besides, Galnet was enlarged with 750 extra verbal idioms, most of them synonyms or variants of the former. In this study, we present the working methodology for the experiment and an analysis of the results, to help understand the most important problems found when trying to introduce idioms in Galnet. We also discuss the reasons preventing the inclusion of some expressions, and the criteria used to introduce the idioms that finally made it into the network.