Substantives migrate between declensions, verbs between conjugations. The familiar examples of paradigms are the conjugations of verbs and the declensions of nouns. The different conjugations differ in some tenses. See Japanese consonant and vowel verbs for more information about verb groups and their conjugations. There are two conjugations and 11 irregular verbs. There were four weak verb conjugations and six groups of strong verbs. There are three regular sets of verbal conjugations, and various verbs are irregularly conjugated. Aromanian verbs are classified in four conjugations. Plurals, verb conjugations, and other inflections are ranked separately. Verbs can be semantically classified based on certain conjugations. Verbs occur in some 38 different conjugations. The two main conjugations of verbs in present and past tense were also present. Korean has only ten irregular forms of conjugation except for the passive and causative conjugations. Romanian has four verbal conjugations which further split into ten conjugation patterns. The I-shift affects verbs only in their singular conjugations.