From Reduplication Wikipedia, the free encyclopedia (selected quotes)
Reduplication in linguistics is a morphological process in which the root or stem of a word (or part of it) or even the whole word is repeated exactly or with a slight change.
Reduplication is used in inflections to convey a grammatical function, such as plurality, intensification, etc., and in lexical derivation to create new words.
English has several types of reduplication, ranging from informal expressive vocabulary (the first four forms below) to grammatically meaningful forms (the last two below).
Rhyming reduplication: hokey-pokey, razzle-dazzle, super-duper, boogie-woogie, teenie-weenie, walkie-talkie, hoity-toity, wingding, ragtag. Although at first glance "Abracadabra" appears to be an English rhyming reduplication it in fact is not; instead, it is derived from the Aramaic formula "Abəra kaDavəra" meaning "I would create as I spoke."
Exact reduplications (baby-talk-like): bye-bye, choo-choo, night-night, no-no, pee-pee, poo-poo. Couscous is not an English example for reduplication, since it is taken from a French word which has a Maghrebi origin.
Ablaut reduplications: bric-a-brac, chit-chat, criss-cross, ding-dong, jibber-jabber, kitty-cat, knick-knack, pitter-patter, splish-splash, zig-zag, flimflam. In the ablaut reduplications, the first vowel is almost always a high vowel and the reduplicated ablaut variant of the vowel is a low vowel.
Shm-reduplication can be used with most any word; e.g. baby-shmaby, cancer-schmancer and fancy-schmancy. This process is a feature of American English from Yiddish, starting among the American Jews of New York City, then the New York dialect and then the whole country.
Only the last of the above types is productive, meaning that examples of the first three are fixed forms and new forms are not easily accepted.
Comparative reduplication: In the sentence "John's apple looked redder and redder," the reduplication of the comparative indicates that the comparative is becoming more true over time, meaning roughly "John's apple looked progressively redder as time went on." In particular, this construction does not mean that John's apple is redder than some other apple, which would be a possible interpretation in the absence of reduplication, e.g. in "John's apple looked redder." With reduplication, the comparison is of the object being compared to itself over time. Comparative reduplication always combines the reduplicated comparative with "and". This construction is common in speech and is used even in formal speech settings, but it is less common in formal written texts. Although English has simple constructs with similar meanings, such as "John's apple looked ever redder," these simpler constructs are rarely used in comparison with the reduplicative form. Comparative reduplication is fully productive and clearly changes the meaning of any comparative to a temporal one, despite the absence of any time-related words in the construction. For example, the temporal meaning of "The frug seemed wuggier and wuggier" is clear: Despite not knowing what a frug is or what wugginess is, we know that the apparent wugginess of the frug was increasing over time, as indicated by the reduplication of the comparative "wuggier".
Contrastive focus reduplication: Exact reduplication can be used with contrastive focus (generally where the first noun is stressed) to indicate a literal, as opposed to figurative, example of a noun, or perhaps a sort of Platonic ideal of the noun, as in "Is that carrot cheesecake or carrot CAKE-cake?". This is similar to the Finnish use mentioned below. Another, from Seinfeld Scripts: "I mean...Do you like him or do you like him like him?"  An extensive list of such examples is found in .
More can be learned about English reduplication in Thun (1963), Cooper and Ross (1975), and Nevins and Vaux (2003).
Reduplicative babbling in child language acquisition
During the period 25–50 weeks after birth, all 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 'didididi'. 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.
Proud residents of the town often brag about it as "the town so nice they named it twice". Walla Walla is a Native American name that means "Place of Many Waters". The original name of the town was Steptoeville named after Colonel Edward Steptoe.
The name comes from a word "walatsa," which means "running."
Walatsa is a word in the Shahaptian language, which was spoken by several native tribes that lived along the rivers in SE Washington, NE Oregon, and W Idaho. One of those tribes was called the Walla Wallas.
I couldn't find enough information to confirm whether the word "running" referred to the nearby Walla Walla River, or the Walla Walla people who lived along it.
Walla Walla isn't just a city; it's an entire county and also a river valley in the southeast corner of Washington State.
“Walla Walla” was a Nez Perce name given to one of the indigenous groups who lived in what is now the Walla Walla Valley. The name means “running waters” or, more specifically, the place where a small stream runs into a larger one. A number of rivers flow across the valley into the Walla Walla River and join the Columbia River. In addition to the Walla Wallas, native North American groups who lived in this area included the Nez Perce, the Cayuses, and Umatillas. In 1806, the Lewis and Clark expedition camped near the mouth of the “Wallahwollah river” on the Columbia and encountered the “honest and friendly ... Wallah wallahs.”
Walla Walla is an Indian name meaning "many waters." In 1805, when Lewis and Clark traveled by the mouth of a small river flowing into the Columbia River, they met a group of Indians who told them their name for the small river was "Wallah Wallah." So Lewis and Clark called the Indian tribe by the same name as the river.
Al Jolson, a famous entertainer, years ago visited here and allegedly said it was "the town so nice they named it twice."
Although these settlers first named the township Ebenezer after their hometown in South Australia, its name was changed to Walla Walla (Aboriginal for "place of many rocks") because another township with the same name existed in New South Wales.
kinnikinnick is also a reduplication and, in some spellings, a palindrome: kinninnik and kinuk-kinuk. Kinnikinnick is a mixture of dried leaves, sometimes bark, and later tobacco smoked by Algonquian Indians and pioneers in the Ohio Valley (M-W). The name was also applied to one of the plants commonly used in the mixture, Arctostaphylos uva-ursi, also called bearberry. The genus name Arctostaphylos comes from the Greek words for bear, arktos, and for a bunch of grapes staphylos (or staphyle), while the specific epithet uva-ursi comes from the Latin words for grape, uva, and bear, ursus (source 1; source 2). The plant has an extensive range throughout North America, except for the South and Lower Midwest (source 3: USDA range map) with rare populations in Georgia (source 4). It's also found in Eurasia and the mountains of Guatemala (source 2 above).