Czech nouns, adjectives, most pronouns and some numerals are declined, i.e. they form cases. Cases are the word forms with specific endings. Czech is a synthetic language with flexible word order, and therefore it needs cases with their endings as "signals" that express grammatical relationships between words. All Czech verbs are conjugated. The conjugation means that the verb changes its ending and thus expresses different persons. Personal pronouns (e.g. já, ty, on etc.) are in Czech, unlike many other languages, usually not used with verbs because the person's information is expressed by the verb ending.