The English sentence "John and Bill carried three suitcases" is ambiguous.  John and Bill may have split a total of three suitcases between them, or they may each have carried three suitcases.  Many languages, like Georgian, use <i>distributive numerals</i> to draw out the second meaning: 

<br><br><i>Romanma da Zurabma sam-sami Äanta caiÉ£o.</i> 'Roman.ERG and Zurab.ERG DISTR-three.ABS suitcase.ABS carry.PST.3SG' for 
<br>(i)"Roman and Zurab carried three suitcases each."
<br>(ii)"Roman and Zurab carried the suitcases three by three."

<br><br>The distributive numerals create a different ambiguity, as demonstrated by interpretations (i) and (ii).  Roman and Zurab may each have carried three suitcases, or sets of three suitcases may have been carried an unspecified, potentially infinite number of times.

<br><br>If we define distributive numerals in terms of a "share" and a "key," the ambiguity is clarified.  In English, the distribution would be read as the share <i>per</i> key.  In sentence (i), the key is the NP "Roman and Zurab," which indicates that there were three suitcases <i>per</i> person.  In sentence (ii), the key is the verb "carried," which indicates that there were three suitcases <i>per</i> act of carrying, regardless of how many times it occurred.

<br><br><b>Reference</b><br>
Gil, David. 2008. Distributive Numerals.
In Haspelmath et al (2008), chapter 54. Available online at <a href="http://wals.info/feature/54">
http://wals.info/feature/54</a href>.
