Appendix:Vietnamese reduplication

Reduplication (láy âm) in Vietnamese consists of several patterns and was/is used extensively to create từ láy (“reduplicative”). This article outlines some common patterns of reduplication and their function.

Reduplication in Vietnamese can involve some alterations of rimes, consonants (initials and finals) and tones. The six tones of Northern Vietnamese can be divided into three categories and two registers. The three categories can be conveniently referred to as A (ngang and huyền), B (sắc and nặng) and C (hỏi and ngã). The two B tones each have two allotones in complementary distribution: one in checked syllables (those that end in the stops ⟨-p⟩, ⟨-t⟩, ⟨-ch⟩, ⟨-c⟩) and one in the rest. These checked allotones can be alternatively analyzed as a separate D category; in such analysis, the Northern dialects have eight tones and four tone categories (with reduction in many dialects; for Southern dialects, seven tones due to the merger of C1 and C2, for many North Central dialects, seven tones due to the merger of B2 and C2). In traditional Vietnamese poetry, A tones are called bằng, while B and C tones are collectively grouped as trắc. The two registers are upper (1 or phù) and lower (2 or trầm), originated from the onset voicing differences.

Although terminology may differ, this category and register-based tonal system is basically identical to those of the related Vietic languages, of the Kra-Dai languages, of Middle Chinese and its descendants, and of the Hmong-Mien languages.

Full reduplication

Full reduplication is the most commonly discussed type of reduplication in Vietnamese.

In its most simple form (từ láy toàn bộ), it involves the copying of the entire root: (C)(w)V(C)T > (C)(w)V(C)T-(C)(w)V(C)T. In more complex forms, it involves tonal and coda replacement of the reduplicated syllable (the first syllable in a từ láy).

Nouns, adverbs of frequency and interrogative pronouns

These parts of speech usually only allow simple full reduplication. Its function is often augmentative. It is not productive on nouns and is (party) productive on interrogative pronouns when used non-augmentatively. As full reduplication is generally no longer productive on nouns and pronouns, the reduplicated forms can be considered lemmas. Full reduplication on nouns is literary or formal.

Terms for organisms (often small animals) and some other things were also formed by full reduplication. This process is no longer productive.

Nouns

	Reduplicated form	Root	Note
1.	người người (“people”)	người (“human being, person”)
2.	nơi nơi (“everywhere”)	nơi (“place”)
3.	đêm đêm (“every night”)	đêm (“night”)

Adverbs of frequency

	Reduplicated form	Root	Note
1.	mãi mãi (“forever”)	mãi (“for a long time”)
2.	luôn luôn (“always”)	luôn (“always”)
3.	thường thường (“often”)	thường (“often”)

Interrogative pronouns

	Reduplicated form	Root	Note
1.	đâu đâu (“everywhere”)	đâu (“where”)
2.	ai ai (“everyone”)	ai (“who”)

Reduplicated interrogative pronouns can be used non-augmentatively:

Nó đi đâu đâu rồi ai mà biết.

He went somewhere, who knows [where]?

Cái gì gì mà chị nói bữa trước đó.

The thingy that you told me the other day.

Terms for organisms

	Reduplicated form	Root	Note
1.	chuồn chuồn (“dragonfly”)	chuồn (“dragonfly”)	In isolation, the root is obsolete.
2.	châu chấu (“grasshopper”)	*chấu
3.	bươm bướm (“butterfly”)	bướm (“butterfly”)
4.	nhền nhện (“spider”)	nhện (“spider”)

	Reduplicated form	Root	Note
1.	ròng rọc (“pulley”)	*rọc
2.	bong bóng (“bubble”)	bóng (“ball, bladder”)
3.	chong chóng (“pinwheel”)	chóng (“quick”)

For the alternation of tones and codas, see the section for adjectives below.

Verbs

Verbs allow only simple full reduplication.

Full reduplication of verbs is colloquial and productive. As reduplication is productive, the reduplicatives are not considered lemmas.

Verbs

	Reduplicated form	Root	Note
1.	ăn ăn (“to keep on eating”)	ăn (“to eat”)
2.	nói nói (“to keep on talking”)	nói (“to talk”)
3.	viết viết (“to keep on writing”)	viết (“to write”)

Adjectives

Full reduplication is productive with all monosyllabic adjectives that can be used in isolation: that excludes Sino-Vietnamese compounds such as khẩn cấp or polysyllabic reduplicatives like vui vẻ, but includes those like hiền.

Simple full reduplication (C)(w)V(C)T > (C)(w)V(C)T-(C)(w)V(C)T is operative on adjectives as mentioned, but adjectives also allow alternation of tone or/and coda of the root word on the reduplicated syllable.

The function of full reduplication on adjectives is typically diminutive. As this type of reduplication is productive, reduplicatives should be entered as soft redirects using the template {{vi-rdp of}}.

	Reduplicated form	Root	Note
1.	hay hay (“kinda good, kinda interesting”)	hay (“good, interesting”)
2.	mềm mềm (“softish”)	mềm (“soft”)
3.	nóng nóng (“somewhat hot”)	nóng (“hot”)
4.	chật chật (“kinda tight”)	chật (“tight”)

If the root has the structure (C)(w)V(N)T, where N is an optional nasal and T is a tone from the trắc category, the tone change can occur on the reduplicated syllable. The tone change must be from B (sắc and nặng) or C (hỏi and ngã) (trắc tones) on the root to A (ngang and huyền, known as bằng tones) on the reduplicated syllable and the changed tone must belong to the same register as the root syllable's tone (i.e. from sắc and hỏi to ngang, from nặng and ngã to huyền).

With N

	Reduplicated form	Root	Note
1.	nham nhám (“kinda rough”)	nhám (“rough”)	B1 (sắc) > A1 (ngang)
2.	mìn mịn (“kinda fine, kinda smooth”)	mịn (“smooth, fine”)	B2 (nặng) > A2 (huyền)
3.	âm ẩm (“kinda damp”)	ẩm (“damp”)	C1 (hỏi) > A1 (ngang)
4.	loàng loãng (“kinda watery”)	loãng (“watery”)	C2 (ngã) > A2 (huyền)

Without N

	Reduplicated form	Root	Note
1.	thôi thối (“kinda smelly”)	thối (“smelly”)	B1 (sắc) > A1 (ngang)
2.	nhè nhẹ (“kinda light”)	nhẹ (“light”)	B2 (nặng) > A2 (huyền)
3.	đo đỏ (“reddish”)	đỏ (“red”)	C1 (hỏi) > A1 (ngang)
4.	dề dễ (“fairly easy”)	dễ (“easy”)	C2 (ngã) > A2 (huyền)

If the root syllable is checked (i.e. it ends in ⟨-p⟩, ⟨-t⟩, ⟨-ch⟩, ⟨-c⟩) then the reduplicated syllable may be formed with a homorganic nasal.

Full reduplication on checked syllables

	Reduplicated form	Root	Note
1.	mầm mập (“kinda fat”)	mập (“fat”)	⟨-p⟩ > ⟨-m⟩
2.	nhàn nhạt (“kinda bland”)	nhạt (“bland”)	⟨-t⟩ > ⟨-n⟩
3.	lềnh lệch (“kinda deviated”)	lệch (“deviated”)	⟨-ch⟩ > ⟨-nh⟩
4.	điêng điếc (“having bad ear”)	điếc (“deaf”)	⟨-c⟩ > ⟨-ng⟩

Trisyllabic reduplication

Sometimes, trisyllabic reduplicatives can be generated from monosyllabic roots. This type of reduplication is partly productive.

The tone of first syllable is B1 (sắc) while the second syllable carries A2 (huyền) tone. If the root syllable is checked, the coda of the second syllable would be a homorganic nasal. Deviated from this is sạch sành sanh, which has become idiomatic and fixed (although the expected sách sành sạch is also attested).

Trisyllabic reduplication

	Reduplicated form	Root	Note
1.	sạch sành sanh (“completely empty”)	sạch (“clean”)
2.	hết hền hệt (“not a thing left”)	hết (“all gone, all”)
3.	sát sàn sạt (“extremely close”)	sát (“very close”)
4.	tuốt tuồn tuột (“all and everything”)	tuốt (“all”)
5.	hót hòn họt (“hottest, very trendy”)	hót (“hot, popular”)	< English hot
6.	ngón ngòn ngon (“very delicious”)	ngon (“tasty”)

AABB reduplication

A small number of disyllabic words (mostly adjectives) allow AABB reduplication, where each of the two syllables is repeated.

Reduplicated form	Root	Notes
hùng hùng hổ hổ (“very fierce”)	hùng hổ (“fierce”)	both root and reduplicated form seem to be borrowed from Chinese 熊熊虎虎/熊虎 (xiónghǔ)
dập dập dềnh dềnh	dập dềnh (“bobbing”)
gồ gồ ghề ghề	gồ ghề (“bumpy”)

-iếc reduplication

⟨-iếc⟩ reduplication is operative in almost any monosyllabic nouns and verbs that can be used in isolation. The reduplicated syllable is formed by replacing the entire rime (may or may not includes the on-glide -w-) with ⟨-iếc⟩: (C)(w)V(C)T > (C)(w)V(C)T-(C)(w)iếc. ⟨-iếc⟩ reduplication can be blocked if the rime of root is already ⟨-iếc⟩.

As reduplication is productive, the reduplicatives are not considered lemmas. Its function is dismissive, i.e. "[noun] and such petty things" or "such stupid [noun]".

-iếc reduplication

	Reduplicated form	Root	Note
1.	phim phiếc (“movies and such stupid things”)	phim (“movie”)
2.	mèo miếc (“cats and such stupid things”)	mèo (“cat”)
3.	cá kiếc (“fish and such stupid things; betting (which is a stupid thing to do)”)	cá (“fish; to bet”)
4.	game ghiếc (“games, gaming (which one thinks is stupid)”)	game (“game”)

-a reduplication

⟨-a⟩ reduplication is operative in disyllabic roots (usually adjectives or verbs). There are two types of roots where this type of reduplication can be used:

• Disyllabic roots with identical rime and similar tone, i.e. the root structure is C₁RT₁-C₂RT₂ where R is an identical rime in both syllables, T₁ and T₂ belong to the same register or the same tone category. After undergoing ⟨-a⟩ reduplication, ⟨-a⟩ replaces the rime of the second syllable of the root, thus the reduplicative obtains the structure of C₁RT-C₂a-C₁RT-C₂RT. ⟨-a⟩ can take either ngang or huyền tone, depending on the register of the tones of the root.
• Disyllabic roots with identical onset and the tones of both syllables must belong to the same register, i.e. the root structure is CR₁T₁-CR₂T₂, where C is an identical onset in both syllables, T₁ and T₂ belong to the same register. After undergoing ⟨-a⟩ reduplication, ⟨-a⟩ replaces the rime of the second syllable of the root, thus the reduplicative obtains the structure of CR₁T₁-Ca-CR₁T₁-CR₂T₂. ⟨-a⟩ can take either ngang or huyền tone, depending on the register of the tones of the root.

As this type of reduplication is (generally) productive, reduplicatives should be entered as soft redirects using the template {{vi-rdp of}}. Its function is often generalizing or augmentative.

-a reduplication type 1

	Reduplicated form	Root	Note
1.	lúc nha lúc nhúc	lúc nhúc (“abound around, all over”)	⟨-uc⟩ rime, sắc tone
2.	loăng qua loăng quăng	loăng quăng (“to wander, to run around aimlessly”)	⟨-oăng⟩ rime, ngang tone
3.	càu nhà càu nhàu	càu nhàu (“to complain”)	⟨-au⟩ rime, huyền tone

-a reduplication type 2

	Reduplicated form	Root	Note
1.	bập bà bập bùng	bập bùng	⟨b-⟩ onset, B2/D2 (nặng) and A2 (huyền) belong to lower register
2.	hối ha hối hả	hối hả	⟨h-⟩ onset, B1 (sắc) and C1 (hỏi) belong to upper register
3.	dập dà dập dìu	dập dìu	⟨d-⟩ onset, B2/D2 (nặng) and A2 (huyền) belong to lower register
4.	khục khà khục khặc	khục khặc	⟨kh-⟩ onset, both syllables carry nặng tone

There is also a variant of -a reduplication type 1 where the rimes of both syllables of C₁RT₁-C₂RT₂ are replaced by ⟨-a⟩:

-a reduplication type 1 variant

	Reduplicated form	Root	Note
1.	tùm lum tà la	tùm lum (“all over the place”)	⟨-um⟩ rime, A2 (huyền) and A1 (ngang) belong to same tone category. Typical type 1 tùm la tùm lum can also be used.
2.	lang thang la tha	lang thang (“to wander”)	⟨-ang⟩ rime, ngang tone.
3.	lung tung la ta	lung tung (“disorderly, chaotic”)	⟨-ung⟩ rime, ngang tone. Typical type 1 lung ta lung tung can also be used.

-ung reduplication

This pattern appears to be marginally productive or is only starting to become productive, since reduplicatives can be generated from recent loanwords. Reduplicatives of this kind often convey an informal tone and are somewhat diminutive but not as strongly dismissive as -iếc reduplication.

This pattern seems to be most compatible with roots with labial onset, i.e. ⟨m-, b-, ph-⟩, so mèo mủng (“cat (diminutive)"”) is attested but *chó chủng ("dog (diminutive)") does not sound "right". As with -iếc, this pattern does not seem to be subjected to tonal assimilation.

Exceptional cases like game gủng (“games and stuff”) also exist.

-ung reduplication

	Reduplicated form	Root	Note
1.	fan phủng (“fans and the likes”)	fan (“fans, supporters”)	< English fan
2.	mưa mủng (“rain and stuff”)	mưa (“rain”)
3.	phim phủng (“movies and stuff”)	phim (“movie, film”)
4.	bánh bủng (“pastries and such stuff”)	bánh (“pastry, bread, cake”)

Reduplication of compounds

"Roots" of this pattern are time-related compounds. This pattern is of little productivity but is not completely unproductive, as some of these "compounds" are not idiomatic.

Reduplication of compounds

	Reduplicated form	"Root"	Note
1.	ngày xửa ngày xưa (“long ago, once upon a time”)	ngày xưa (“the old days”)
2.	ngày nảy ngày nay (“these very days”)	ngày nay (“these days”)
3.	năm nảo năm nao (“some year from a long time ago”)	năm nào (“some year”)
3.	đời nảo đời nao (“from time immemorial”)	đời nào (“long time ago”)

Other patterns

Vietnamese features numerous other patterns, none are currently (fully) productive.

The onset replacement patterns, aside from ⟨l-⟩ reduplication, are completely unproductive. On the other hand, the rime replacement patterns currently have low productivity, although it is likely that all (or at least most) of them never achieve full productivity in the first place and always have low productivity.

Each rime replacement "suffix" has an inherent tone that is subjected to tonal assimilation to the tone of the root. For example, in ngon nghẻ, the root ngon with upper register tone A1 (ngang) is reduplicated with the suffix ⟨-e⟩ bearing an inherent C tone, the resulted reduplicated syllable ⟨nghẻ⟩ therefore has tone C1 (hỏi), belongs to the same register as the root, while in lặng lẽ, the root lặng has lower register tone B2 (nặng), so the reduplicated syllable has C2 (ngã).

Patterns can be progressive (i.e. the root is the first syllable), such as -ang reduplication, or anticipatory (i.e. the root is the second syllable), like all the onset replacement patterns and -âp reduplication.

l- reduplication

⟨l-⟩ reduplication is probably the most commonly encountered type of onset replacement reduplication. Lemmas generated from this kind of reduplication is still used extensively in both written and spoken Vietnamese. Its function is typically generalizing.

l- reduplication

	Reduplicated form	Root	Note
1.	luống cuống (“hurry”)	cuống (“in hurry”)
2.	lảm nhảm (“to talk nonsense”)	nhảm (“nonsensical”)
3.	loanh quanh (“to walk around”)	quanh (“around”)
4.	lớp nhớp (“sticky and mucky”)	nhớp (“mucky”)
5.	lao nhao (“in disarray”)	nhao (“to make noise by talking loudly”)
7.	lốm đốm (“spotty”)	đốm (“spot”)
8.	lờ nhờ (“pretty unclear, pretty dull”)	nhờ (“unclear, dull”)
9.	loắt choắt	choắt (“small, shrivelled”)
10.	lẩm bẩm (“to mumble”)	bẩm (“to tell, to say”)
11.	lòng vòng (“to go around”)	vòng (“circle; winding”)
12.	lục đục (“having internal conflicts”)	đục (“opaque, murky”)

ch- reduplication

ch- reduplication

	Reduplicated form	Root	Note
1.	chộn rộn (“bustling”)	rộn (“noisy, bustling”)
2.	chới với (“to struggle, to lose balance”)	với (“to reach out”)
3.	chật vật (“toilsome, strenuous”)	vật (“to wrestle”)

t- reduplication

The function of this pattern appears to be intensive. For examples, mút (“tip”) > tút mút (“tip-top > very far away, almost invisible”), máy (“to touch”) > táy máy (“to be touchy-feely”).

This pattern seems to be most compatible with roots with m- onset.

t- reduplication

	Reduplicated form	Root	Note
1.	tò mò (“curious”)	mò (“to grope”)
2.	tờ mờ (“in the early morning”)	mờ (“dim, blurred”)
3.	tủn mủn (“petty, finicky; crumbly”)	mủn (“crumbling, deteriorated”)
4.	táy máy (“to be touchy-feely”)	máy (“to touch, to move”)

b- reduplication

b- reduplication

	Reduplicated form	Root	Note
1.	bồn chồn (“uneasy, restless”)	chồn
2.	bối rối (“be at loss, bewildered”)	rối (“tangled”)
3.	bộp chộp (“impetuous, rash”)	chộp (“to grab”)

-eo reduplication

The reduplicated syllable must carry a C tone.

-eo reduplication

	Reduplicated form	Root	Note
1.	trắng trẻo (“fair”)	trắng (“white”)	B1 (sắc) > C1 (hỏi)
2.	trong trẻo (“clear, pure”)	trong (“transparent”)	A1 (ngang) > C1 (hỏi)
3.	xinh xẻo (“pretty”)	xinh (“pretty”)	A1 (ngang) > C1 (hỏi)
4.	lạnh lẽo (“cold”)	lạnh (“cold”)	B2 (nặng) > C2 (ngã)

-ang reduplication

The reduplicated syllable must carry an A tone.

-ang reduplication

	Reduplicated form	Root	Note
1.	mở mang (“to expand”)	mở (“to open”)	C1 (hỏi) > A1 (ngang)
2.	hở hang (“revealing”)	hở (“uncovered”)	C1 (hỏi) > A1 (ngang)
3.	mỡ màng (“greasy”)	mỡ (“fat”)	C2 (ngã) > A2 (huyền)
4.	lỡ làng (“interrupted; unsuccessful”)	lỡ (“to miss”)	C2 (ngã) > A2 (huyền)

-e reduplication

The reduplicated syllable must carry a C tone.

-e reduplication

	Reduplicated form	Root	Note
1.	mát mẻ (“cool”)	mát (“cool”)	B1 (sắc) > C1 (hỏi)
2.	vui vẻ (“joyous, joyful”)	vui (“joyful, happy”)	A1 (ngang) > C1 (hỏi)
3.	mạnh mẽ (“strong”)	mạnh (“strong”)	B2 (nặng) > C2 (ngã)
4.	sạch sẽ (“clean”)	sạch (“clean”)	B2 (nặng) > C2 (ngã)

-ăn reduplication

The reduplicated syllable must carry a B tone. Reduplicatives generated from this pattern seem to carry certain "positive" connotation, denoting qualities considered good or preferable. This is noticeable especially when the root itself does not possess inherently positive connotation, such as nhỏ (“small”) > nhỏ nhắn (“tiny, petite, small and cute”), vuông (“square”) > vuông vắn (“fittingly square, appropriately square”).

một cái bàn vuông ― a square table

một cái bàn vuông vắn ― a nice and square table

-ăn reduplication

	Reduplicated form	Root	Note
1.	may mắn (“lucky”)	may (“lucky”)	A1 (ngang) > B1 (sắc)
2.	chín chắn (“mature”)	chín (“ripe”)	B1 (sắc) > B1 (sắc)
3.	đứng đắn (“upstanding”)	đứng (“to stand”)	B1 (sắc) > B1 (sắc)
4.	khoẻ khoắn (“healthy, energized”)	khoẻ (“healthy”)	C1 (hỏi) > B1 (sắc)
5.	dày dặn (“nice and thick”)	dày (“thick”)	A2 (huyền) > B2 (nặng)
6.	vừa vặn (“fitting”)	vừa (“fitting, moderate”)	A2 (huyền) > B2 (nặng)

-ơm reduplication

The reduplicated syllable must carry a B tone. Reduplicatives generated from this pattern seem to carry certain "negative" connotation, denoting qualities considered bad or undesirable. This is noticeable especially when the root itself does not possess inherently negative notation, such as hay (“good, interesting”) > hay hớm (“interesting”) (with ironic connotation and used chiefly with negative constructions).

-ơm reduplication

	Reduplicated form	Root	Note
1.	hay hớm (“interesting”)	hay (“good, interesting”)	A1 (ngang) > B1 (sắc)
2.	thẳng thớm (“straight”)	thẳng (“straight”)	C1 (hỏi) > B1 (sắc)
3.	lì lợm (“obstinate”)	lì (“impudent, obtuse”)	A2 (huyền) > B2 (nặng)
4.	nghịch ngợm (“mischievous”)	nghịch (“mischievous”)	B2 (nặng) > B2 (nặng)
5.	người ngợm (“self, body”)	người (“human, body”)	A2 (huyền) > B2 (nặng)

-a reduplication

The reduplicated syllable must carry a C tone.

-a reduplication

	Reduplicated form	Root	Note
1.	hối hả (“hurried, hasty”)	hối (“to urge”)	B1 (sắc) > C1 (hỏi)
2.	vật vã (“struggling with”)	vật (“to wrestle”)	B2/D2 (nặng) > C2 (ngã)
3.	nền nã (“well-mannered”)	nền (“foundation, basis”)	A2 (huyền) > C2 (ngã)
4.	vội vã (“in a hurry”)	vội (“in a hurry”)	B2 (nặng) > C2 (ngã)

-âp reduplication

The reduplicated syllable is a checked syllable and therefore must carry the checked allophone of a B tone.

Reduplicatives generated from this pattern usually signify instability (thấp thoáng) or movements, especially up-and-down (nhấp nhô), left-and-right (chập choạng), inside-and-outside (thập thò).

-âp reduplication

	Reduplicated form	Root	Note
1.	nhấp nháy (“to blink”)	nháy (“to flash”)	B1 (sắc) > D1 (sắc)
2.	mấp mô (“bumpy”)	mô (“mound”)	A1 (ngang) > D1 (sắc)
3.	mấp máy (“to move lightly and quickly”)	máy (“to move”)	B1 (sắc) > D1 (sắc)
4.	dập dềnh (“to bob”)	dềnh	A2 (huyền) > D2 (nặng)
5.	mập mờ (“dim, unclear”)	mờ (“dim, blurred”)	A2 (huyền) > D2 (nặng)

-ap reduplication

The reduplicated syllable is a checked syllable and therefore must carry the checked allophone of a B tone. Most roots have a labial coda (i.e. -p and -m) and carry a B/D tone; an example that deviates from such template is cứng > cứng cáp.

The reduplicatives seem to imply something that is in a constant state or happens on regular basis, although these implications are often very weak if detecable at all. This can be most clearly seen with nhấm nháp and vấp váp.

-ap reduplication

	Reduplicated form	Root	Note
1.	vấp váp (“to stumble, to trip”)	vấp (“to stumble”)	D1 (sắc) > D1 (sắc)
2.	liếm láp (“to lick”)	liếm (“to lick”)	B1 (sắc) > D1 (sắc)
3.	nhấm nháp (“to nibble on, to take one's time to enjoy the taste”)	nhấm (“to gnaw at”)	B1 (sắc) > D1 (sắc)
4.	ấm áp (“warm”)	ấm (“warm”)	B1 (sắc) > D1 (sắc)
5.	mập mạp (“fat”)	mập (“fat”)	D2 (nặng) > D2 (nặng)

-iêm reduplication

The reduplicated syllable must carry a B tone. The roots are monosyllabic verbs.

-iêm reduplication

	Reduplicated form	Root	Note
1.	đắp điếm	đắp (“to cover”)	B1/D1 (sắc) > B1 (sắc)
2.	đậy điệm	đậy (“to cover”)	B2 (nặng) > B2 (nặng)
3.	giấu giếm	giấu (“to hide”)	B1 (sắc) > B1 (sắc)
4.	âu yếm	âu (“to fondle”)	A1 (ngang) > B1 (sắc)

-ui reduplication

The reduplicated syllable must carry a C tone.

-ui reduplication

	Reduplicated form	Root	Note
1.	ngắn ngủi (“brief”)	ngắn (“short”)	B1 (sắc) > C1 (hỏi)
2.	gần gũi (“close, nearby”)	gần (“near”)	A2 (huyền) > C2 (ngã). There is also the variant gần gụi, which probably originated from a dialect of the North Central region, where C2 (ngã) and B2 (nặng) frequently merge.

-inh reduplication

The reduplicated syllable must carry a C tone. Some roots appear to have become obsolete or archaic as free morphemes, replaced by their reduplicated counterparts.

-inh reduplication

	Reduplicated form	Root	Note
1.	lém lỉnh (“smart and playful”)	lém	B1 (sắc) > C1 (hỏi)
2.	hóm hỉnh (“humorous”)	hóm	B1 (sắc) > C1 (hỏi)
3.	ngộ nghĩnh (“funny-looking”)	ngộ (“weird, strange”)	B2 (nặng) > C2 (ngã)
4.	hợm hĩnh (“haughty”)	hợm (“haughty”)	B2 (nặng) > C2 (ngã)
5.	vòi vĩnh (“to ask, to clamor”)	vòi (“to ask, to beg”)	A2 (huyền) > C2 (ngã)
6.	tròn trĩnh (“very round, plump”)	tròn (“round”)	A2 (huyền) > C2 (ngã)

-o reduplication 1

The reduplicated syllable must carry an A tone.

-o reduplication 1

	Reduplicated form	Root	Note
1.	hay ho (“nice, interesting”)	hay (“good, interesting”)	A1 (ngang) > A1 (ngang)
2.	ốm o (“very skinny, bony”)	ốm (“thin, skinny”)	B1 (sắc) > A1 (ngang)
3.	gay go (“difficult, tough”)	gay (“difficult”)	A1 (ngang) > A1 (ngang)
4.	gầy gò (“skinny”)	gầy (“thin”)	A2 (huyền) > A2 (huyền)

-o reduplication 2

The reduplicated syllable must carry a B tone.

-o reduplication 2

	Reduplicated form	Root	Note
1.	cau có	cau (“to frown”)	A1 (ngang) > B1 (sắc)
2.	nhăn nhó	nhăn (“to frown, to grimace”)	A1 (ngang) > B1 (sắc)
3.	quạu quọ	quạu (“irritated”)	B2 (nặng) > B2 (nặng)
4.	vẹo vọ	vẹo (“twisted, crooked”)	B2 (nặng) > B2 (nặng)

-oi reduplication 1

The reduplicated syllable must carry an A tone.

-oi reduplication 1

	Reduplicated form	Root	Note
1.	hiếm hoi	hiếm (“rare”)	B1 (sắc) > A1 (ngang)
2.	thiệt thòi	thiệt (“mistreated, handicapped”)	B2/D2 (nặng) > A2 (huyền)
3.	nhỏ nhoi	nhỏ (“small”)	C1 (hỏi) > A1 (ngang)
4.	lẻ loi	lẻ (“alone”)	C1 (hỏi) > A1 (ngang)

-oi reduplication 2

The reduplicated syllable must carry a C tone.

-oi reduplication 2

	Reduplicated form	Root	Note
1.	rắn rỏi (“hardened, firm, stable”)	rắn (“hard, solid”)	B1 (sắc) > C1 (hỏi)
2.	ít ỏi (“few, scant”)	ít (“few”)	B1/D1 (sắc) > C1 (hỏi)
3.	cứng cỏi (“resilient, tough”)	cứng (“hard”)	B1 (sắc) > C1 (hỏi)
4.	rành rõi (“well-versed”)	rành (“to know clearly”)	A2 (huyền) > C2 (ngã)

-ôi reduplication

The reduplicated syllable must carry a B tone.

-ôi reduplication

	Reduplicated form	Root	Note
1.	tức tối	tức (“upset, angry”)	B1/D1 (sắc) > B1 (sắc)
2.	bực bội	bực (“upset, irritated”)	B2/D2 (nặng) > B2 (nặng)
3.	nực nội	nực (“(of weather) hot and oppressive”)	B2/D2 (nặng) > B2 (nặng)
4.	chật chội	chật (“tight, narrow”)	B2/D2 (nặng) > B2 (nặng)

-ung reduplication

The reduplicated syllable must carry an A tone.

Many roots seem to have tone B2 or D2 (nặng).

-ung reduplication

	Reduplicated form	Root	Note
1.	não nùng	não (“sorrowful”)	C2 (ngã) > A2 (huyền)
2.	lạnh lùng	lạnh (“cold”)	B2 (nặng) > A2 (huyền)
3.	thẹn thùng	thẹn (“shy, embarassed”)	B2 (nặng) > A2 (huyền)
4.	mịt mùng	mịt (“dark, gloomy”)	B2/D2 (nặng) > A2 (huyền)

-it reduplication

The reduplicated syllable is a checked syllable and therefore must carry the checked allophone of a B tone. This "suffix" has the allograph ⟨-yt⟩ after the labial semivowel.

-it reduplication

	Reduplicated form	Root	Note
1.	xoắn xuýt	xoắn (“twisted”)	B1 (sắc) > B1/D1 (sắc)
2.	xúm xít	xúm (“to gather”)	B1 (sắc) > B1/D1 (sắc)
3.	qua quýt	qua (“to get over with”)	B1 (sắc) > B1/D1 (sắc)
4.	rậm rịt	rậm (“dense”)	B2 (nặng) > B2/D2 (nặng)