Apart from vocabulary and grammar, the irregular verbs are one of the fundamentals basics that should be mastered when learning English. Here is a tool that can help you learn these verbs by heart. As its name suggests, Irregular Verbs is a list of English irregular verbs. In its database, it contains more than 200 verbs that you can also edit, delete or add irregular verbs. To learn these verbs, you have two options, either you learn it by heart by using the list or you do the exercises. At any rate, if you choose one of these methods, you will have 3 levels of difficulty. Irregular Verbs is free.