Case markers often distinguish between the various arguments of a predicate, such as the Agent and Patient. Three basic types of arguments are generally distinguished: the subject of a transitive clause, the object of a transitive clause, and the subject of an intransitive clause. 

<br><br>A few languages use tone to distinguish these case markings.  In the following Nandi examples, only tone indicates which NPs are the subject and object.

<br><br>a) <i>kè:r-éy kípe:t la:kwé:t</i> 'look.at-IMP Kipet-SUBJ  child-NONSUBJ' for "Kibet is looking at the child."
<br>b) <i>kè:r-éy kipe:t kípro:no</i> 'look.at-IMP Kibet.NONSUBJ Kiprono.SUBJ' for "Kiprono is looking at Kibet."

<br><br><b>Reference</b><br>
Dryer, Matthew S.. 2008. Position of Case Affixes.
In Haspelmath et al (2008), chapter 51. Available online at <a href="http://wals.info/feature/51">
http://wals.info/feature/51</a href>.

