Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Spanish verbs are a complex area of Spanish grammar, with many combinations of tenses, aspects and moods (up to fifty conjugated forms per verb). While conjugation rules are relatively straightforward, a large number of verbs are irregular. Among these, some fall into more-or-less defined deviant patterns, while others are uniquely irregular. This article tries to summarize the common irregular patterns. As in all Romance languages, many irregularities in Spanish verbs can be retraced to Latin grammar.