Page 166 - The International Journal of the Royal Society of Thailand Vol.XIII-2021

The International Journal of the Royal Society of Thailand
Volume XIII – 2021

Why do we have both ไ- and ใ- as vowels when they are pronounced in the
same way?

Why do all 4 tone marks not dictate the same tone in all cases? For

example, in the words ข่า and ป่า we pronounce the 1 tone mark (- ่) as a
st
low-tone but for ค่า and น่า we use the same tone mark as a high tone.

In this article the historical approach will be proposed to explain the Thai
writing system in order to answer these questions and also to explain the overall

concept of the Thai writing system.

As this article mentions both letters and speech sounds, to avoid any
confusion, these terms are used separately with different meanings:

letters speech sounds
consonant letter (CL) consonant (C)

vowel form vowel
tone mark tone

2. From the Indian to Thai alphabet

The Thai alphabet evolved from that of an ancient Indian script called the
The International Journal of the Royal Society of Thailand iland The International Journal of the Royal Society of Thailand The International Journal of the Royal Society of Thailand
The International Journal of the Royal Society of Tha
The International Journal of the Royal Society of Thailand
Pallava script or Grantha script which was used in the Pallava dynasty (Diringer,
Volume X - 2020 2020 Volume X - 2020 Volume X - 2020
Volume X - 2020
Volume X -
1968: 314-5) that ruled the southern India kingdom from 300-888 CE. (Basham,
2 2 2 2 2
t
sy
a
a
e
sy

h
l
ll
be
h
Indian alphabet, the Thai alphabet is an alpha-syllabary systemem
, th
Indian alphabet, the Thai alphabet is an alpha-syllabary system in which each consonant in which each consonant in which each cons
an
a
ha
p
lp
a
st
-
lp
is
a
e
Th
y
t
ndi
a
n a
a
I
b
i
Indian alphabet, the Thai alphabet is an alpha-syllabary system in which each consonant onant
b
r

a
Indian alphabet, the Thai alphabet is an alpha-syllabary system in which each consonant
2000: xx) Like the Indian alphabet, the Thai alphabet is an alpha-syllabary system
3
letter not only stands for only a consonant but also a vowel or so-called inherent vowe
letter not only stands for only a consonant but also a vowel or so-called inherent vowel, l, letter not only stands for only a consonant but also a vowel or so-called inherent vowel, letter not only stands for only a consonant but also a vowel or so-called inherent vowel,
letter not only stands for only a consonant but also a vowel or so-called inherent vowel,
in which each consonant letter not only stands for only a consonant but also a
x
m
p
e
we
o

en
l
al
g
er
en
th
v
we
y
a
o
/
e
r
. F
generally the vowel /a/. For example: mple:
o

v
/
al

th
generally the vowel /a/. For example:
. F
o
a
er
l
x
/
r
e
g
a
l
y
generally the vowel /a/. For example: le:
e
/
l
a
vowel or so-called inherent vowel, generally the vowel /a/. For example:

ŋa
ग ga ga
ख kha a
घ gha a gha
ka

an
āg
ख kha
Devanāgarī script ript Devanāgarī script
ī sc
क ka
D
ग ga ग ga
Devanāgarī script
Devanāgarī script
a
ङ ŋ ङ ŋa ङ ŋa
r
e
v
घ gha gha
Devanāgarī script क ka क ka क ka क ka ख kh khakhaख kha ग ga ga घ gh gha ङ ŋa a ङ ŋa

ख
घ
ग
घ
Pallava script
ka kha ga gha ŋa
Pallava script a script ka ka ka ka ka kha a kha kha ga ga ga ga ga gha a gha gha
ŋa ŋa ŋa ŋa ŋa
Pallava script ript Pallav
a
P
sc
ll
gh gha
a
Pallava script
v
a
kh kha

In almost all of the alphabetical systems of India, the consonant letters will inh
In almost all of the alphabetical systems of India, the consonant letters will inherit
In almost all of the alphabetical systems of India, the consonant letters will inherit erit In almost all of the alphabetical systems of India, the consonant letters will inherit In almost all of the alphabetical systems of India, the consonant letters will inherit
/
o

e
we
ound

n
h
n
av
,
ss
le
ss
le
e
we
,
n
th
th
e
e
a
/

o f
/
s
;
l
/
a
s
o f
ound
av
e

h
a
l
e
l
n
o
;
a
e
, th
v

ng
ng

the vowel /a/; nonetheless, we have also found out that Bengali script, the script used in in
e
t
o

t

e
B
sc
e
e
a
i
c
p
r
l
r
i
th
s
c
i
t
l
p
, th
e
s
a
i
th
r
i
the vowel /a/; nonetheless, we have also found out that Bengali script, the script used in used in
h
d
r

a
o
l

se
u
out
we

t
pt
i
sc
t
v
B
out

a
h
pt
t
we
the vowel /a/; nonetheless, we have also found out that Bengali script, the script used in
3 It is also called abugida which is suggested by Peter T. Daniels (1990: 730 cited in Richard Salomon, 1998:
a
.
r
it
s
a
e
in
i
495)
1990:
1990:
n,
h
in

e
a
495)
n,
,
m
r
h

o
we
d
a
e
d
l

v
/
we
o
f
o
/

st
in

/
in
ɔ
ɔ
l
a
st
/
/
e
(
l
th
s
K
e

l
m
a
i
K
a
it
/

e
/

f
o
a
a
(
th

v
/

d
lt
n
e
ri
the Ganges river delta, inherits the vowel /ɔ/ instead of /a/ (Klaiman, 1990: 495). Fo. For the Ganges

lt
g
e
a
r
th
r
e
e
v
ri
the Ganges river delta, inherits the vowel /ɔ/ instead of /a/ (Klaiman, 1990: 495). For For
d
v
Ga
e
,
s
e

the Ganges river delta, inherits the vowel /ɔ/ instead of /a/ (Klaiman, 1990: 495). For r
15f)
example:
ex
example: e: e:
example: am l p l
p
ex
am

156 Bengali script ক kɔ ɔ খ khɔ গ gɔ ɔ ঘ ghɔ ɔ ghɔ ঘ gh ঘ ghɔ ঘ ঘ ghɔ ঙ ŋ ঙ ŋɔ ঙ ŋɔ ঙ ŋɔ
Bengali script
ক k ক kɔ ক kɔ ক kɔ
The Thai Writing System: Reasons behind Its Systemɔ khɔ Bengali script
a
Bengali script ript
li
g
sc
খ kh খ khɔ খ খ khɔ
B
গ g গ gɔ গ gɔ গ gɔ
n
e
ঙ ŋɔ ɔ

As do Thai consonant letters. But the reason that each Thai consonant letter

As do Thai consonant letters. But the reason that each Thai consonant letter r tter As o d o Th Th a i c n o so n a n n a t le tt e tt r s e . r s B u B t t t h t e h e eas eas n o n t h at h each Th Th i a c i o c n o so n a n n a t le
i c
a
n
t le
at
As do Thai consonant letters. But the reason that each Thai consonant lettet letter
each
.
n
a
t
n
o
o
As
n
u
d
r
so
r
so

inherits the vowel /ɔː/ may not be directly influenced by the Bengali script but more likely
inherits the vowel /ɔː/ may not be directly influenced by the Bengali script but more likely ely inherits the vowel /ɔː/ may not be directly influenced by the Bengali script but more likely inherits the vowel /ɔː/ may not be directly influenced by the Bengali script but more likely
inherits the vowel /ɔː/ may not be directly influenced by the Bengali script but more lik
m
o
bodi
th
n
n
th
a

ie
a
e
b
a
n
al
In
h
f
r o
f
r
m
t

t
C
a
n
C
a
y
m
A
th
A
e
bodi

th
K
a
e
o
r

m
e

r o
K
c
h
l
t
r
Kh
a
sy
sc

ic
ic
t
t
r
ip
n
et
a
r
by that of Ancient Khmer script. In the Khmer or Cambodian alphabetical system, each , m ,
m
r
st
e

e
m
e
e
Kh
l

sy
m
st
sc
h
ab
t
In
by that of Ancient Khmer script. In the Khmer or Cambodian alphabetical system, each each each
.
n
p
al
p
y
.
b
h
c
ab
ie
ip
et
by that of Ancient Khmer script. In the Khmer or Cambodian alphabetical system, each
e
n
k
e
a
g
li
t
Th
b
c
r

so
n
n
r
li
t
g
o
will
oup
o
a
c
k
i
e
th
a
n
consonant letter will inherit the vowel /ɔː/. Unlike Thai, there will be a certain group of roup of
e

n
a
consonant letter will inherit the vowel /ɔː/. Unlike Thai, there will be a certain group of of
i,

e
so
e
th
a
c
i,
r

consonant letter will inherit the vowel /ɔː/. Unlike Thai, there will be a certain group of
b
e
a
Th
n
i
e

r
t
e
c
r
a
a
will
e
n
will
th
ɔ
e
r
/
v
/

r

ː

.
t
th
it
o
/
we
r
tt
l
e
we
le
l
ː
o
e
e

v
ɔ
tt
will
in
h
r
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n
le

e
h
.
it
/
e
in
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e

na
e
o
o
r
h
m

ic
r
th
a
n
r
e
s
o
s
it
r v
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r
ic
it
r
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o

e
h
r
e
,
n
nd
n
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ː
s
/
a
a
a
th
nd

t le
a
tt
t in
a

tt
ː
Khmer consonant letters that inherits the vowel with a clear voice /ɔː/, and another that at at
ɔ
e
/
th
e
h
o
ɔ
a
,
th
/
n
t le
/
s
ons
a
le
v
ons
a
e
le
we
a
l with
v

th
c
m
h
r

o

c

l with
r v
e

c
we
e
na
o
o
c
r

e
Khmer consonant letters that inherits the vowel with a clear voice /ɔː/, and another that th th th
Khmer consonant letters that inherits the vowel with a clear voice /ɔː/, and another that
p
th
it
v
l wit
am
/
th
/
we
v
e
a
968:

inherits the vowel with a breathy voice /ɔ ː/ (Jacob, 1968: 27-8). For example:
y
r
s
ɔ
b

c
(
s
a
inherits the vowel with a breathy voice /ɔ ː/ (Jacob, 1968: 27-8). For example: am l p l

th
c
h
e

Ja

a
ob,
ob,
968:
re
ː

a
l wit

(
1
1
/
re

h
Ja
th
b

h
ic
7
ɔ
o
).
2
h
F
in
F
o
r
v
o
r

o
).
we
/
ic
8
v

e
7

e
o
8
in
-
-
e
inherits the vowel with a breathy voice /ɔ ː/ (Jacob, 1968: 27-8). For example: e: e:
r
ex
2
y

ː
e
it
ex

o

X ghɔ ː ɔgh
x khɔː
g ŋɔ ː g ŋɔ ː g ŋɔ ː
K gɔ̀ː K gɔ̀ː K gɔ̀ː
Khmer script ript Khmer script
X
e
r
gh
x khɔː ɔːkh
x
Khmer script
x
m
Kh
Khmer script sc k kɔː k kɔː k kɔː k kɔː x khɔː kh K gɔ̀ː K gɔ̀ː ɔː X ghɔ ː X g ŋɔ ː g ŋɔ ː ː ɔ ː
k kɔː
X ghɔ ː

2 2 2 2 2 t is t is ls a o c o a c a lle abugi da da hi w c hi c h i s ugge s t e s d t e b d y P y e P e e r T r . T D . a D a e ni s e ( l s 1 ( 9 1 0 9 9 7 : 3 7 c 0 i c e i d i d i n R ha c r ha r S d a l S a
d
l
I
d
t
:
s

w
t
t
ls
e
a
i
0

b
I
c
It is also called abugida which is suggested by Peter T. Daniels (1990: 730 cited in Richard Salomon, lomon,
ugge
3

n R
s
s
ni
lle
e
t
It is also called abugida which is suggested by Peter T. Daniels (1990: 730 cited in Richard Salomon,

d
0
i
It is also called abugida which is suggested by Peter T. Daniels (1990: 730 cited in Richard Salomon, omon,
9
abugi
h i

1998:
1998: 15f) 1 1
1998: 15f) 5f) 5f)
1998: 15f)
1998:
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