by the oblique forms. In addition, Patients of verbs cast in the agent focus are indefinite. There are four affixes in this focus category: ag-, -um-, mang- and ma-. Roots will prefer to take only one or some of the prefixes. In some cases the meaning changes from one affix to another, for example, ngisit, black. If ag- is affixed, agngisit, the meaning is that of there is a likelihood of becoming black or to darken, for example Nagngisitka, You darkened. However, with -um-, ngumisit, the meaning becomes more of a possibility or conjecture, Ngumisngisitkansa iti tengnat' aldaw, You might get darker at midday. Ag- The verbal prefix ag- is very productive and can verbalize a large number of roots. If a new word were to enter the language, most likely this is the prefix used to verbalize it, for example, the fictitious baz: agbaz to "baz". If the root takes either ag- or -um-, the additional meaning of ag- are some of the following: Repetition of the action Long duration of the action With some roots, the attainment of the root, for example, dakkel, big, agdakkel to be big, doktor doctor, agdoktor to be a doctor. The actor is in full control (internally motivated) The certainty of the action because it is habitually occurring or frequently occurring. Denotes the action taken on with the root, palsiit blowgun, agpalsiit to shoot with the blowgun, use the blowgun. (Compare with -um- below.) <Um> The verbal prefix <um>, is inserted, or infixed, to the first syllable of the root. Some of the meanings imparted using this infix are: A single action or an action that is not as long in duration as what is denoted by ag-. With certain roots, using <um> denotes the act of "becoming" the root, for example, lakay old man, lumakay to grow older, to become older (said of males), to become an old man. The actor is externally or circumstantially motivated. The possibility of the action. (Compare with ag- above.) Ag- Versus <Um> The affixes ag- and <um> are very similar. Many verbs take either and have little difference in meaning. Other verbs are drastically differentiated. Below is a chart contrasting the two. Mang- The mang- prefix is used to denote the following: Collection or gathering Purchase Movement Occupation and identification The final nasal, , of the prefix commonly becomes the homoorganic nasal of the first consonant