The charts below show the way in which the
International Phonetic Alphabet (IPA) represents Vietnamese language pronunciations in Wikipedia articles. There are two major standards, one of Hanoi and one of Saigon. Each makes distinctions that the other does not; represented here are the central dialects that make the distinctions of both. Following the examples are common alternate transcriptions of these sounds in the IPA for comparison.
Vietnamese phonology for a more thorough look at the sounds of Vietnamese.
ch [ (Saigon final tɕ] [ after t] e/i/y ) 
y (may follow all vowels but e/i/y ) 
c (after u, ô) [kʷ]
n (Saigon final [ after ŋ] a/o/u ) 
nh (Saigon final [ after after n] e/i/y ) 
ng (after u, ô) [ŋʷ]
s (Hanoi [) s]
t (Saigon final [ after k] a/o/u ) 
tr [ (Hanoi ʈ] ) c
v (Saigon [) j]
u (Hanoi initial [ʔw]) (may follow all vowels but a/o/u ) 
g (before a/o/u ),  gh (before e/i/y ) 
d (Saigon [) j]
r (Hanoi ) z
g (before e/i ) 
iê, final ia
ươ, final ưa [ɉə]
uô, final ua
a (Hanoi [˧], Saigon [˧])
à (Hanoi [˧˩], Saigon [˧˩])
á (Hanoi [˧ˀ˥], Saigon [˧˥])
a᷉ ə᷉ 
ả (Hanoi [˧˩˧], Saigon [˧˩˧])
ã (Hanoi [˧ˀ˥], Saigon [˧˩˧])
ạ (Hanoi [˧ˀ˩], Saigon [˧˩˧ˀ])
ấc (Hanoi , Saigon )
ậc (Hanoi [˨], Saigon )
↑ अ आ इ ई उ The front vowels ( [, i] [, e] [, ɛ] [) which are based on the letters j] e, i, and y.
↑ अ आ इ ई The non-front vowels, which are based on the letters a, o, and u.
↑ This is a dipping tone. It looks similar to ã ə̃ ( [ ̃ ] ( nasalized mark). The dipping tone differs only in being angular in shape, but is not widely supported by IPA fonts.
↑ अ आ Before a final /p, t, c, k/, the six tones of Vietnamese are reduced to two.