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

<br><br>In languages like Hungarian, which has <i>mixed</i> relator morphemes, at least one of the relators is syncretistic and codes for both comitative and instrumental.  At least one other relator codes for comitative or instrumental relation alone:

<br><br>a) Instrument: "Comitative-Instrumental" 
<br><i>Tol-<b>lal</b> ír-ok.</i> 'pen-<b>WITH</b> write-1SG' for "I am writing <b>with</b> a pen."
<br>b) Accompaniment: "Comitative-Instrumental" 
<br><i>Jan is megjelenik barát-já-<b>val</b>.</i> 'Jan also appear.3SG friend-POSS.3SG-<b>WITH</b>' for "Jan too shows up <b>with</b> his friend."
<br>c) Accompaniment: "Associative"
<br><i>Csónak-ház-ak sport-és játszóter-ek vár-ják család-<b>ostul</b> gyerek-<b>estül</b> az ember-ek-et.</i> 'boat-house-PL sport-ADJ playground-PL wait-3PL family-<b>WITH</b> child-<b>WITH</b> DEF man-PL-ACC' for "Boathouses and sports grounds are waiting for the people <b>with</b> family and children."    

<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>.
 