Reduplication is found in a wide range of languages and language groups, though its level of linguistic productivity varies. Examples of it can be found at least as far back as Sumerian, where it was used in forming some color terms, e.g. babbar "white", kukku "black".[2]
https://en.wikipedia.org/wiki/Reduplication
Copying direction
A reduplicant can copy from either the left edge of a word (left-to-right copying) or from the right edge (right-to-left copying). There is a tendency for prefixing reduplicants to copy left-to-right and for suffixing reduplicants to copy right-to-left:
At 25–50 weeks after birth, typically developing infants go through a stage of reduplicated or canonical babbling (Stark 198, Oller, 1980). Canonical babbling is characterized by repetition of identical or nearly identical consonant-vowel combinations, such as nanana or idididi. It appears as a progression of language development as infants experiment with their vocal apparatus and home in on the sounds used in their native language. Canonical/reduplicated babbling also appears at a time when general rhythmic behavior, such as rhythmic hand movements and rhythmic kicking, appear. Canonical babbling is distinguished from earlier syllabic and vocal play, which has less structure.
English has several types of reduplication, ranging from informal expressive vocabulary (the first four forms below) to grammatically meaningful forms (the last two below). See also the alliteration section of the irreversible binomial article for cases like flip-flop, dribs and drabs, etc.
- Rhyming reduplication: Artsy-fartsy, boogie-woogie, okey-dokey, easy-peasy, hanky-panky, hocus-pocus, hoity-toity, hokey-pokey, holy moly, hurdy-gurdy, itsy-bitsy, namby-pamby, raggle-taggle, ragtag, razzle-dazzle, super-duper, teenie-weenie, willy-nilly, wingding.
- Exact reduplications: Ack ack, aye-aye, back-to-back,
blah-blah, boo-boo, bye-bye, chin-chin, choo-choo, chow-chow, dik-dik,
doo-doo, fifty-fifty, gogo, ha ha, half-and-half, honk-honk,
housey-housey, juju, klop-klop, mama, muumuu, night-night, no-no, papa, pee-pee, pip-pip, pom-pom, poo-poo, pooh-pooh, putt putt, so-so, ta-ta, there-there, tut-tut, tutu, wah-wah, wee-wee, yo-yo. While in many forms of English, exact reduplications can also be used to emphasise the strength of a word ("He wants it now now"), in South African English, 'now-now' means 'relatively soon'.
- lexical reduplication: 'Each-each boy take one-one chair.' Indian English
- Ablaut reduplications: In ablaut reduplications, the first vowel is almost always a high vowel (typically ɪ as in hit) and the reduplicated vowel is a low vowel (typically æ as in cat or ɒ as in top). Examples include: bric-a-brac, chit-chat, clip-clop, ding-dong, flimflam, flip-flop, hip-hop, jibber-jabber, kitty-cat, knick-knack, mishmash, ping-pong, pitter-patter, riffraff, sing-song, slipslop, splish-splash, tick-tock, ticky-tacky, tip-top, whiff-whaff, wibble-wobble, wishy-washy, zig-zag. Three-part ablaut sequences are less numerous, but are attested, e.g. tic-tac-toe, bing-bang-boom, bish-bash-bosh, splish-splash-splosh[13] and "Live, Laugh, Love". Spike Milligan's poem "On the Ning Nang Nong" achieves comic effect by varying the ordering of vowels in such triples: There's a Nong Nang Ning/Where the trees go Ping!.
- Shm-reduplication can be used with most any word; e.g. baby-shmaby, cancer-shmancer and fancy-shmancy. This process is a feature of American English from Yiddish, starting among the American Jews of New York City, then the New York dialec
