Where the deverbal noun is derived by means of the agentive suffix the verb is almost invariably in the third person singular form, which is to say, not marked for number. Plurality in these forms is normally marked only by the use of the duo-plural agentive suffix in place of singular . Zero-derived agentive nouns may show plurality by means of subject markers. For example, "shaman" may be either , with an overt agentive suffix, but the zero-marked is more common. There are two plural forms: , with the duo-plural agentive suffix, and , in which the zero-marked form is based on the plural form of the verb.