but partially overt cases of secondary origin can be observed too. The number of noun classes in individual languages range from two to eight. Regarding grammatical number, there may be a distinction between singular and plural, plurality itself may impact the class to which a noun belongs. In some cases, a grammatical collective is seen. Many languages distinguish local versus functional cases, and to some degree also casus rectus versus casus obliquus. The inflectional paradigms are often based on partially classifying productive stem extensions (absolutive and oblique, ergative and genitive inflection. Localization is mostly conveyed by postpositions, but it can be also partly based on preverbs. Noun phrases exhibit incomplete class agreement, group inflection (on the noun) with partial attributive oblique marking, which may, in turn, carry a partially determining function. Verbs do not agree with person, with a few exceptions like Lak, in which first and second persons are marked with the same suffix and verbs agree with the P argument, and Hunzib in which verbs agree with A argument. Evidentiality is prominent, with reported, sensory and epistemic moods all appearing as a way of conveying the evidence. Epistemic modality is often tied to the tense. Ergativity Most Northeast Caucasian languages exhibit an ergative–absolutive morphology. This means that objects of transitive sentences and subjects of intransitive sentences both fall into a single grammatical case known as the absolutive. Subjects of transitive sentences, however, carry a different marking to indicate that they belong to a separate case, known as the ergative. This distinction can be seen in the following two Archi sentences. Note that objects and subjects of intransitive sentences carry no suffix, which is represented by the null suffix, -∅. Meanwhile, agents of transitive sentences take the ergative suffix, -mu. Noun classes Northeast Caucasian languages have between two and eight noun classes. In these languages, nouns are grouped into grammatical categories depending on certain semantic qualities, such as animacy and gender. Each noun class has a corresponding agreement prefix, which can attach to verbs or adjectives of that noun. Prefixes may also have plural forms, used in agreement with a plural noun. The following table shows the noun–adjective agreement paradigm in the Tsez language. Unusual agreement targets In many Northeast Caucasian languages, as well as appearing on adjectives and verbs, agreement can also be found on parts of speech which are not usually able to agree in other language