# kar

'kar' is an agentive suffix, so can never appear on its own but can only be applied to a stem (usually noun or verb) to mean the 'doer of' like -er in English (eg, make-kar = maker/creator; story-kar = writer/author). So akar is the thing that produces the 'a' sound. 'Matra', on the other hand, is a general term meaning any vowel sign and can be used on its own, as in "We use the matra form of the vowel when attached to a consonant." But amatra and akar are synonymous.
