Tricky wording: Dum or gươm?

There is a point of view that both initial consonants d and gi are pronounced as /z/, Northerners can distinguish between d and gi so they pronounce and write correctly as "dườm" ; while Southerners, because they cannot distinguish, mistakenly write "ườm" as "đưm" .

In fact, there were intellectuals of Northern origin who wrote for me , not for them , for example: "Please go and tell the judge for me" - Nha Nho (1943, p.90) by Chu Thien (originally from Nam Dinh); "Pham Lai, please help me"; "Please say it for me" - Essay on Kim Van Kieu (1943, p.160) by Dao Duy Anh (originally from Thanh Hoa); "Think of the new Hao Tu for So-Luc" - Chu Dich (1969, volume 2) by Phan Boi Chau (originally from Nghe An)...

Not only did books and newspapers published in the North use the word "dum" , but so did the South. In 1958, the magazine Bach Khoa (in Saigon) "promoted" the word "dum" everywhere: "coi dum; xem dum; nuong dum; xem dum"... (issues 277 - 287, p.74).

Please note, the word "dum" also has other meanings. For example: "Nên is one husband and one wife, one niu com tam (broken rice) and one dum mam nem" ( Cau hat gop - 1901 by Huynh-Tinh Paulus Cua, p.23); "Nàng-dùm", the name of a floating rice variety ( Inventory: Foreign Seeds and Plants Imported - 1922, volumes 61-70, p.46), also known as "Nàng Tây Đùm" ( Institute of Climate Change , An Giang province)...

In general, from the late 19th century onwards, the word "dum" appeared commonly in books and newspapers, but only "giùm" was considered the correct spelling. Why?

Based on the dictionary, we see that in the Nom script system, there is almost no word " dum" , only "duom" (𢵳) with the meaning "to help, to do for". In Dai Nam Quoc Am Tu Vi (1895), there is also no word "duom" , only "duom" with the meaning "to help". Similarly, " duom" meaning "to ask (to borrow, to ask, to order) to do for you" (commissionner) appears in Petit dictionnaire français-annamite - 1885, part 4 by Truong Vinh Ky (p.410); "to gather firewood for you", "to break firewood for you" ( Chuyen giai buon - 1886 by Huynh-Tinh Paulus Cua, p.49); and "to help, to do for you" is found in Dictionnaire annamite-français - 1899 by Jean Bonet (p.229)...

The word "giùm " also has other meanings. For example: "giùm hoa" (a bunch of flowers: flowers tied together) or a "bouquet" (bouquet) - Dictionnaire franco-tonkinois illustré - 1898 by PG Vallot, p.35; "bo nguoi" (a set of skirts and toys tied together on a string, usually hung around the neck) - Dai Nam Quoc am tu vi , op. cit.

Is it true that "dum" and "duom" are an ambivalent phenomenon in Vietnamese, both words are considered to be correctly spelled (this word appears first, the latter due to phonetic variation), similar to: "troi dat - troi giất"; "hang ngay - hang ngay"; even the way of naming ethnic groups also has variations (K'Ho - Cơ Ho); or in the transcription (bu-gi - buji) or dialect (bu - bầu; troi - gioi)... Writers and poets also write differently about spelling: "dong song" ( My writing life by Nguyen Hien Le, 2006, p.47) - "giong song" ( Giong song Thanh Thuy by Nhat Linh - 1961); "Dong to" ( Cao Chu-than thi-tap , vol. 1, by Cao Ba Quat - 1971, p.366) - "Giong to" (Vu Trong Phung, Ha Noi weekly - 1936)...

In short, if we consider "duom" - "giùm" as meaning "to help", then this pair of words is not a dual phenomenon, because only " duom" is correctly spelled and recorded in the dictionary, while "dum " is not. In other words, "dum" is an incorrect spelling, originating from "writing as it is said"; written according to books and newspapers (maybe the author wrote it correctly but the typesetter made a mistake or the author wrote it wrong?). In any case, please note: "giùm " is the correct spelling today.

Source: https://thanhnien.vn/lat-leo-chu-nghia-dum-hay-gium-18525022122205097.htm