Onomatopoeic expressions, similar to words in English like `bang, crash, thud, whiz, zap, zonk, crunch', etc., are formed in Tamil by prefixing the onomatopoeic item before ýá -nnu. The structure of these emulates a `quotative' construction, i.e., it is as if there is a sound of some sort being quoted.
Many more examples of such expressions can be found; what is interesting about these expressions is that they are often phonologically aberrant. That is, the phonological structure of some of these expressions violates the usual rules about morpheme structure in Tamil---retroflex consonants can occur in initial position, some consonants are voiced initially, consonants occur finally without automatic vowels, and in general, the usual phonological constraints about what are possible words in Tamil are suspended.
Often these expressions are used where adverbs in English would be more common, as in ÷Õ§èýá Éç¡Þ jill-nnu irukku for `it's chilly' or Ë£åýá umm-nnu for `seriously, quietly, like a bump on a log'.
ÇÂç ß£¾Ô Ë£åýá Ð¡´Ôÿ»Õ´Õ¥Üçÿ»Ôç
avaru summaa umm-nnu okkaandikittrundaaru
`He just say there like a bump on a log.'
Some expressions, when reduplicated, have slightly different meaning, i.e., ¹¡Þýá takku-nnu can mean `knock, knock' but ¹¡Þ¹¡Þýá takku-takku-nnu means `regularly, like clockwork, with mechanical efficiency'.There is one published work on reduplication in LT, Malten 1989; Kausalya Hart (ms.) also has hundreds of examples of these in ST.