Comitatives and instrumentals are morphemes, typically case affixes or adpositions, that express the semantic relations between participants of an event.  Comitatives show accompaniment, while instrumentals mark an NP as the instrument used by an agent to complete an action.  

<br><br>In languages like Inga, which demonstrate the trait of <i>identity</i>, the relator morphemes for comitatives and instrumentals are identical:

<br><br>a) Accompaniment:
<br><i>Alcalde-<b>huan</b>-ta-si pueblo-ma samuncuna</i> 'mayor-<b>WITH</b>-even-QUO town-ALL come.3PL' for "They came to town together <b>with</b> the mayor."
<br>b) Instrument:
<br><i>Caspi-<b>hua</b>-si tanteancuna ñayapa junda</i> 'stick-<b>WITH</b>-QHO measure.3PL how full' for "It was so full, they were measuring it <b>with</b> a tree-trunk."

<br><br>Glossing convention: Comitatives and Instrumentals will be  glossed WITH.

<br><br><b>Reference</b><br>
Stolz, Thomas & Stroh, Cornelia & Urdze, Aina. 2008. Comitatives and Instrumentals.
In Haspelmath et al (2008), chapter 52.
Available online at <a href="http://wals.info/feature/52">
http://wals.info/feature/52</a href>.
