Editing Vietnamese language (section)

===Consonants===
The [[syllable]]-initial ''ch'' and ''tr'' digraphs are pronounced distinctly in the North-Central, Central, and Southern varieties but are merged in Northern varieties, which pronounce them the same way). Many North-Central varieties preserve three distinct pronunciations for ''d'', ''gi'', and ''r'', but the Northern varieties have a three-way merger, and the Central and the Southern varieties have a merger of ''d'' and ''gi'' but keep ''r'' distinct. At the end of syllables, the palatals ''ch'' and ''nh'' have merged with the alveolars ''t'' and ''n'', which, in turn, have also partially merged with velars ''c'' and ''ng'' in the Central and the Southern varieties.

{| class="wikitable" style="text-align: center;"
|+ Regional consonant correspondences{{Anchor|Regional consonant correspondences}}
! Syllable position !! Orthography !! Northern !! North-central !! Central !! Southern
|-
! rowspan=8 | syllable-initial
! ''x''
| rowspan=2 | {{IPA|[s]}}
| colspan=3 | {{IPA|[s]}}
|-
! ''s''
| colspan=2 | {{IPA|[ʂ]}} || {{IPA|[s, ʂ]}}{{efn|name="retroflex"|In southern dialects, ''ch'' and ''tr'' are increasingly being merged as {{IPA|[c]}}. Similarly, ''x'' and ''s'' are increasingly being merged as {{IPA|[s]}}.}}
|-
! ''ch''
| rowspan=2 | {{IPA|[t͡ɕ]}}
| colspan=3 | {{IPA|[c]}}
|-
! ''tr''
| colspan=2 | {{IPA|[ʈ]}} || {{IPA|[c, ʈ]}}{{efn|name="retroflex"}}
|-
! ''r''
| rowspan=3 | {{IPA|[z]}}
| colspan=3 | {{IPA|[r]}}
|-
! ''d''
| {{varies}}
| rowspan=2 colspan=3 | {{IPA|[j]}}
|-
! ''gi''
| {{varies}}
|-
! ''v''
| colspan=3 | {{IPA|[v]}}
| {{IPA|[v, j]}}{{efn|In the southern dialects, ''v'' is increasingly pronounced {{IPA|[v]}} among educated speakers. Less educated speakers use {{IPA|[j]}} more consistently throughout their speech.}}
|-
! rowspan=12 | syllable-final
! ''t''
| colspan=2 | {{IPA|[t]}}
| rowspan=2 colspan=2 | {{IPA|[k]}}
|-
! ''c''
| colspan=2 | {{IPA|[k]}}
|-
! style="line-height: 1em;" | ''t'' <br /><span style="font-weight: normal; font-size: small;">after ''i'', ''ê''</span>
| colspan=2 | {{IPA|[t]}}
| rowspan=2 colspan=2 | {{IPA|[t]}}
|-
! ''ch''
| colspan=2 | {{IPA|[k̟]}}
|-
! style="line-height: 1em;" | ''t'' <br /><span style="font-weight: normal; font-size: small;">after ''u'', ''ô''</span>
| colspan=2 | {{IPA|[t]}}
| rowspan=2 colspan=2 | {{IPA|[kp]}}
|-
! style="line-height: 1em;" | ''c'' <br /><span style="font-weight: normal; font-size: small;">after ''u'', ''ô'', ''o''</span>
| colspan=2 | {{IPA|[kp]}}
|-
! ''n''
| colspan=2 | {{IPA|[n]}}
| rowspan=2 colspan=2 | {{IPA|[ŋ]}}
|-
! ''ng''
| colspan=2 | {{IPA|[ŋ]}}
|-
! style="line-height: 1em;" | ''n'' <br /><span style="font-weight: normal; font-size: small;">after ''i'', ''ê''</span>
| colspan=2 | {{IPA|[n]}}
| rowspan=2 colspan=2 | {{IPA|[n]}}
|-
! ''nh''
| colspan=2 | {{IPA|[ŋ̟]}}
|-
! style="line-height: 1em;" | ''n'' <br /><span style="font-weight: normal; font-size: small;">after ''u'', ''ô''</span>
| colspan=2 | {{IPA|[n]}}
| rowspan=2 colspan=2 | {{IPA|[ŋm]}}
|-
! style="line-height: 1em;" | ''ng'' <br /><span style="font-weight: normal; font-size: small;">after ''u'', ''ô'', ''o''</span>
| colspan=2 | {{IPA|[ŋm]}}
|}

In addition to the regional variation described above, there is a merger of ''l'' and ''n'' in certain rural varieties in the North:{{sfnp|Kirby|2011|p=382}}

{| class="wikitable" style="text-align: center;"
|+ ''l'', ''n'' variation
! Orthography
! "Mainstream" varieties
! Rural varieties
|-
! ''n''
| {{IPA|[n]}}
| rowspan="2" | {{IPA|[l]}}
|-
! ''l''
| {{IPA|[l]}}
|}

Variation between ''l'' and ''n'' can be found even in mainstream Vietnamese in certain words. For example, the numeral "five" appears as ''năm'' by itself and in compound numerals like ''năm mươi'' "fifty", but it appears as {{lang|vi|lăm}} in {{lang|vi|mười lăm}} "fifteen" (see [[Vietnamese grammar#Cardinal]]). In some northern varieties, the numeral appears with an initial ''nh'' instead of ''l'': {{lang|vi|hai mươi nhăm}} "twenty-five", instead of the mainstream {{lang|vi|hai mươi lăm}}.{{efn|Gregerson (1981) notes that the variation was present in de Rhodes's time in some initial consonant clusters: ''mlẽ'' ~ ''mnhẽ'' "reason" (cf. modern Vietnamese ''lẽ'' "reason").}}

There is also a merger of ''r'' and ''g'' in certain rural varieties in the South:

{| class="wikitable" style="text-align: center;"
|+ ''r'', ''g'' variation
! Orthography
! "Mainstream" varieties
! Rural varieties
|-
! ''r''
| {{IPA|[r]}}
| rowspan="2" | {{IPA|[ɣ]}}
|-
! ''g''
| {{IPA|[ɣ]}}
|}

The consonant clusters that were originally present in Middle Vietnamese (in the 17th century) have been lost in almost all modern Vietnamese varieties although they have been retained in other closely related [[Vietic languages]]. However, some speech communities have preserved some of these archaic clusters: "sky" is {{lang|vi|blời}} with a cluster in Hảo Nho ([[Yên Mô District|Yên Mô]], [[Ninh Bình Province]]) but ''trời'' in Southern Vietnamese and {{lang|vi|giời}} in Hanoi Vietnamese (initial single consonants {{IPA|/ʈ/, /z/}}, respectively).