Phoneme Frequency Tables

Phoneme Frequency Tables

We've identified two ways to rank the possible spelling of any given phoneme for our data set of over 26,000 words. In the first, we count the number of times a phoneme-grapheme correspondence occurs in the list of words. In the second, we give a weight to each word in the list depending on its frequency in connected text, then multiply each correspodence by that weight.

Why Adding a Frequency Weight Matters

Let's consider the sound /v/, which can be represented by the letter 'v' or the letter 'f'. In our data, there are about 1,700 words that use 'v' and only one word ('of') that uses 'f' (technically two words use this, thereof, being the other). Let's look at an excerpt from "Wizard of Oz" by L. Frank Baum to see why this matters.

When Dorothy stood in the doorway and looked around, she could see nothing but the great gray prairie on every side. Not a tree nor a house broke the broad sweep of flat country that reached to the edge of the sky in all directions. The sun had baked the plowed land into a gray mass, with little cracks running through it. Even the grass was not green, for the sun had burned the tops of the long blades until they were the same gray color to be seen everywhere.

As we can see above, the word 'of' occurs as often as all the other words that include the letter 'v'. It is one of the most common words in English!

So, if you're reading connected text and come across a spelling of the sound /v/, it's just as likely to be spelled with the letter 'f' as it is with the letter 'v'. This is a rather extreme example. Many of the other sounds have similar results regardless of how we rank them, but we can use this data to inform our teaching approaches.

Below you can see the breakdown of each correspondence for the sound /v/. We have a table for the direct frequencies and one for the weighted frequencies.

Grapheme Frequency (total) Frequency (%)
v 1,895 83.19
ve 379 16.64
f 2 0.09
vv 2 0.09
Grapheme Weighted Frequency (total) Weighted Frequency (%)
f 4,137,188.65 43.89
v 3,417,218.52 36.25
ve 1,871,503.80 19.85
vv 111.77 0.00

Frequency Tables by Phoneme

We've run rankings for our entire data set. Below you can find the frequency and weighted frequency for the spellings of each phoneme. You can click on each grapheme to see the words with that correspondence in our Word List Builder.

See our Methodology at the bottom for more details.

Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
a
4,522 99.49 15,973,345.49 98.48
eah
1 0.02 140,297.71 0.86
au
7 0.15 50,817.53 0.31
al
6 0.13 48,540.10 0.30
a.e
8 0.18 6,623.63 0.04
ai
1 0.02 234.18 0.00
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
e
7,695 96.36 13,546,481.08 87.08
ea
213 2.67 685,144.76 4.40
ai
37 0.46 647,964.29 4.17
a
18 0.23 511,055.07 3.29
ie
16 0.20 116,989.03 0.75
ay
1 0.01 46,282.60 0.30
eo
6 0.08 1,610.44 0.01
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
i
10,993 97.43 25,058,728.75 97.33
ee
1 0.01 337,818.60 1.31
y
200 1.77 111,247.43 0.43
i.e
60 0.53 86,354.34 0.34
u
6 0.05 54,100.23 0.21
o
1 0.01 37,722.70 0.15
e
7 0.06 36,908.82 0.14
ei
10 0.09 15,862.87 0.06
ie
5 0.04 6,259.95 0.02
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
o
2,435 97.40 5,488,551.48 94.05
ough
16 0.64 224,265.22 3.84
o.e
3 0.12 46,870.08 0.80
oh
3 0.12 37,990.80 0.65
ow
6 0.24 19,754.47 0.34
oa
15 0.60 8,339.63 0.14
e
18 0.72 7,751.62 0.13
ou
4 0.16 2,148.66 0.04
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
a
1,371 73.95 3,904,064.17 83.89
aw
153 8.25 221,774.25 4.77
au
245 13.21 179,919.49 3.87
al
29 1.56 171,645.97 3.69
ea
28 1.51 85,088.09 1.83
augh
17 0.92 67,099.80 1.44
ah
4 0.22 19,356.51 0.42
awe
3 0.16 3,708.61 0.08
i
4 0.22 1,165.46 0.03
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
o
2,841 29.79 9,270,453.78 29.52
e
404 4.24 7,819,156.56 24.90
a
3,050 31.98 7,496,198.24 23.87
u
2,596 27.22 4,585,763.24 14.60
o.e
47 0.49 1,004,353.68 3.20
ou
330 3.46 633,495.68 2.02
i
136 1.43 214,780.55 0.68
au
8 0.08 126,000.83 0.40
a.e
81 0.85 115,034.59 0.37
u.e
6 0.06 69,400.66 0.22
oo
10 0.10 39,081.15 0.12
ae
5 0.05 12,840.35 0.04
ah
18 0.19 11,751.90 0.04
y
3 0.03 464.74 0.00
ea
1 0.01 376.50 0.00
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
a.e
1,087 24.16 2,632,915.96 25.69
a
2,110 46.90 2,229,953.30 21.76
ay
263 5.85 1,756,625.47 17.14
ai
604 13.43 1,019,999.38 9.95
e.e
20 0.44 753,712.88 7.35
ey
33 0.73 719,377.03 7.02
e
206 4.58 396,630.27 3.87
ei
38 0.84 350,670.87 3.42
ea
52 1.16 308,244.98 3.01
eigh
35 0.78 46,543.66 0.45
aigh
6 0.13 17,774.18 0.17
u
3 0.07 10,386.62 0.10
et
25 0.56 3,979.98 0.04
ee
10 0.22 890.73 0.01
ae
6 0.13 770.22 0.01
ah
1 0.02 147.61 0.00
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
e
2,299 30.95 15,285,567.86 58.45
y
2,236 30.10 4,624,740.85 17.69
ea
728 9.80 2,133,418.46 8.16
ee
632 8.51 1,833,094.70 7.01
i
845 11.38 671,770.31 2.57
e.e
95 1.28 671,051.24 2.57
ie
401 5.40 440,693.22 1.69
ey
86 1.16 153,380.01 0.59
ei
51 0.69 153,258.07 0.59
eo
3 0.04 149,259.13 0.57
i.e
45 0.61 32,625.19 0.12
oe
4 0.05 725.25 0.00
ay
3 0.04 673.47 0.00
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
i
1,096 44.86 5,106,407.83 48.35
i.e
723 29.59 2,267,167.93 21.47
y
284 11.63 1,956,232.02 18.52
igh
177 7.25 866,321.24 8.20
ie
64 2.62 167,006.63 1.58
eye
14 0.57 109,888.85 1.04
ye
9 0.37 29,004.54 0.27
y.e
23 0.94 22,705.28 0.21
ia
15 0.61 14,625.79 0.14
eigh
4 0.16 8,285.49 0.08
ai
13 0.53 5,618.79 0.05
ay
5 0.20 4,532.79 0.04
ei
15 0.61 3,065.75 0.03
oy
1 0.04 295.96 0.00
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
o
2,747 68.81 7,573,100.67 63.03
o.e
482 12.07 1,561,518.84 13.00
ow
257 6.44 1,165,668.94 9.70
ou
67 1.68 850,459.73 7.08
oa
267 6.69 201,056.38 1.67
oh
2 0.05 178,234.58 1.48
a
84 2.10 160,376.31 1.33
oo
26 0.65 127,873.80 1.06
oe
25 0.63 96,967.35 0.81
ough
10 0.25 94,067.25 0.78
eau
10 0.25 3,296.74 0.03
ew
5 0.13 2,324.55 0.02
au
5 0.13 747.25 0.01
eaux
4 0.10 240.93 0.00
aux
1 0.03 62.34 0.00
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
o
93 6.61 5,851,332.99 53.42
ou
62 4.41 3,210,587.67 29.31
oo
392 27.86 601,004.13 5.49
u
475 33.76 471,539.89 4.31
ew
111 7.89 304,548.39 2.78
u.e
135 9.59 183,295.27 1.67
ue
56 3.98 136,131.16 1.24
ough
4 0.28 117,003.02 1.07
ui
46 3.27 52,108.18 0.48
eu
24 1.71 13,349.64 0.12
oe
9 0.64 11,940.47 0.11
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
u
525 74.89 543,969.79 52.44
u.e
105 14.98 301,041.21 29.02
ew
24 3.42 71,091.03 6.85
ue
26 3.71 59,872.59 5.77
eau
3 0.43 56,845.34 5.48
eu
13 1.85 3,162.12 0.30
ou
1 0.14 702.00 0.07
uu
4 0.57 624.14 0.06
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
oul
7 1.85 844,557.35 38.49
oo
173 45.65 836,778.16 38.14
u
189 49.87 433,375.25 19.75
o
9 2.37 79,010.77 3.60
ou
1 0.26 372.43 0.02
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
ou
476 66.39 2,118,680.18 65.58
ow
235 32.78 1,109,280.84 34.33
ough
6 0.84 2,896.92 0.09
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
oi
173 61.79 236,289.39 53.81
oy
107 38.21 202,855.75 46.19
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
er
3,575 66.54 6,348,310.35 63.20
or
567 10.55 894,457.19 8.90
ur
414 7.71 680,971.78 6.78
ir
196 3.65 499,982.17 4.98
ere
2 0.04 442,426.19 4.40
ure
114 2.12 322,807.08 3.21
ar
185 3.44 238,096.03 2.37
re
101 1.88 225,955.37 2.25
ear
58 1.08 215,451.08 2.14
urr
57 1.06 61,109.49 0.61
our
42 0.78 36,263.29 0.36
orr
4 0.07 29,438.42 0.29
err
26 0.48 22,730.04 0.23
ro
5 0.09 11,432.20 0.11
r
12 0.22 6,991.25 0.07
irr
8 0.15 6,011.42 0.06
yr
7 0.13 2,028.91 0.02
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
ure
40 37.38 68,361.53 47.81
ur
52 48.60 55,535.92 38.84
eur
15 14.02 19,083.87 13.35
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
b
3,621 95.54 8,000,670.46 98.76
bu
19 0.50 56,625.68 0.70
bb
150 3.96 43,561.73 0.54
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
p
5,414 92.94 7,653,583.84 93.53
pp
411 7.06 529,593.16 6.47
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
g
1,838 86.70 4,137,225.74 94.30
gu
54 2.55 154,531.06 3.52
gg
187 8.82 62,552.63 1.43
gue
23 1.08 21,300.79 0.49
gh
18 0.85 11,534.29 0.26
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
c
5,238 68.07 6,994,886.99 58.50
k
1,388 18.04 3,800,923.30 31.79
ck
701 9.11 790,049.78 6.61
ch
200 2.60 201,362.41 1.68
cc
101 1.31 143,696.59 1.20
qu
22 0.29 11,699.17 0.10
que
25 0.32 10,189.66 0.09
cu
4 0.05 2,419.37 0.02
q
2 0.03 681.47 0.01
cch
8 0.10 675.35 0.01
kh
6 0.08 536.07 0.00
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
d
6,776 83.63 19,282,173.36 90.47
ed
1,171 14.45 1,834,842.11 8.61
dd
155 1.91 196,857.35 0.92
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
t
11,577 90.86 32,732,034.39 94.91
tt
497 3.90 899,610.63 2.61
ed
621 4.87 785,398.77 2.28
bt
16 0.13 46,590.75 0.14
th
10 0.08 12,934.33 0.04
tte
16 0.13 9,451.01 0.03
pt
4 0.03 2,906.58 0.01
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
f
2 0.09 4,137,188.65 43.89
v
1,895 83.19 3,417,218.52 36.25
ve
379 16.64 1,871,503.80 19.85
vv
2 0.09 111.77 0.00
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
f
2,514 81.02 7,354,131.63 89.78
ff
277 8.93 522,528.12 6.38
ph
283 9.12 175,134.86 2.14
gh
29 0.93 139,360.22 1.70
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
j
452 33.83 938,868.68 43.76
g
524 39.22 586,877.81 27.35
ge
176 13.17 415,327.69 19.36
dge
65 4.87 71,410.22 3.33
d
28 2.10 34,631.80 1.61
gi
22 1.65 34,423.14 1.60
di
6 0.45 22,561.13 1.05
gg
11 0.82 21,099.28 0.98
dg
45 3.37 17,390.26 0.81
dj
7 0.52 2,859.48 0.13
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
ch
703 65.58 1,765,824.98 77.90
t
170 15.86 295,353.04 13.03
tch
184 17.16 151,698.64 6.69
ti
11 1.03 53,668.64 2.37
c
4 0.37 368.16 0.02
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
s
5,044 90.93 10,422,910.17 92.76
se
40 0.72 428,881.77 3.82
z
373 6.72 175,944.15 1.57
es
12 0.22 144,261.57 1.28
ss
12 0.22 28,426.35 0.25
ze
15 0.27 18,519.77 0.16
zz
46 0.83 12,511.16 0.11
x
5 0.09 4,696.22 0.04
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
s
9,050 78.92 16,189,364.43 79.33
c
999 8.71 1,460,588.16 7.16
ss
793 6.92 1,122,354.47 5.50
ce
317 2.76 999,215.87 4.90
se
152 1.33 462,314.74 2.27
st
48 0.42 94,987.84 0.47
sc
86 0.75 72,351.29 0.35
ps
22 0.19 6,525.75 0.03
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
si
84 60.00 93,930.13 50.12
s
29 20.71 85,838.68 45.80
ge
14 10.00 4,754.86 2.54
g
6 4.29 1,035.32 0.55
z
2 1.43 977.69 0.52
ti
2 1.43 415.73 0.22
ci
1 0.71 190.04 0.10
ss
1 0.71 172.42 0.09
j
1 0.71 99.30 0.05
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
sh
896 40.31 1,842,194.29 55.69
ti
989 44.49 967,946.30 29.26
ci
99 4.45 151,152.12 4.57
ssi
69 3.10 120,875.14 3.65
s
19 0.85 106,981.62 3.23
ch
51 2.29 28,867.21 0.87
ss
13 0.58 26,785.12 0.81
sci
12 0.54 20,030.18 0.61
si
22 0.99 12,997.33 0.39
c
15 0.67 12,480.44 0.38
shi
8 0.36 11,314.38 0.34
t
15 0.67 3,222.30 0.10
che
5 0.22 2,163.09 0.07
sc
4 0.18 820.54 0.02
sch
6 0.27 164.97 0.00
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
th
182 90.55 21,536,385.34 99.96
the
19 9.45 8,352.90 0.04
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
th
613 100.00 3,459,762.64 100.00
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
m
4,979 93.70 13,814,607.05 97.91
mm
267 5.02 220,992.16 1.57
mn
15 0.28 40,918.79 0.29
mb
50 0.94 32,874.75 0.23
gm
3 0.06 378.06 0.00
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
m
76 100.00 20,014.66 100.00
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
n
11,101 96.65 31,263,586.76 97.04
kn
61 0.53 630,650.02 1.96
nn
256 2.23 249,982.23 0.78
gn
67 0.58 71,424.35 0.22
pn
1 0.01 382.32 0.00
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
ng
3,122 86.65 4,147,179.02 82.94
n
475 13.18 842,809.66 16.85
ngue
6 0.17 10,445.03 0.21
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
l
6,948 88.21 11,795,867.99 75.91
ll
929 11.79 3,742,899.07 24.09
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
le
808 46.92 1,154,311.28 56.22
al
584 33.91 669,444.00 32.61
el
153 8.89 109,167.69 5.32
il
49 2.85 52,810.01 2.57
l
65 3.77 33,689.68 1.64
all
36 2.09 25,967.40 1.26
ol
7 0.41 6,537.66 0.32
yl
5 0.29 439.02 0.02
ul
7 0.41 355.55 0.02
ell
3 0.17 286.88 0.01
ull
3 0.17 88.48 0.00
ill
2 0.12 1.00 0.00
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
r
9,356 96.28 19,454,735.40 97.02
rr
251 2.58 428,533.07 2.14
wr
94 0.97 165,429.82 0.82
rh
16 0.16 4,538.41 0.02
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
h
1,265 98.60 8,990,513.36 94.15
wh
13 1.01 557,017.71 5.83
j
5 0.39 1,207.69 0.01
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
w
1,094 86.14 8,326,032.84 78.39
wh
126 9.92 2,256,290.21 21.24
u
42 3.31 36,497.98 0.34
o
8 0.63 2,490.70 0.02
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
o.e
6 85.71 570,434.25 88.14
o
1 14.29 76,740.20 11.86
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
y
133 55.65 4,508,439.49 95.91
i
102 42.68 191,206.43 4.07
j
2 0.84 721.60 0.02
ll
1 0.42 332.72 0.01
g
1 0.42 31.18 0.00
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
qu
313 96.01 382,396.37 95.80
cqu
13 3.99 16,782.02 4.20
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
x
607 99.35 719,076.89 99.70
xe
4 0.65 2,138.52 0.30
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
xi
6 60.00 12,089.55 65.94
x
4 40.00 6,245.41 34.06
Phoneme Grapheme Frequency (total) Frequency (%) Weighted Frequency (total) Weighted Frequency (%)
tz
10 45.45 3,306.51 45.95
z
4 18.18 2,095.03 29.11
zz
6 27.27 1,660.25 23.07
ts
2 9.09 134.37 1.87

Methodology

In our data we break each word into its phoneme-grapheme correspondences. We use two rankings to score their frequency: direct and weighted.

For direct ranking:
Frequency (total) - We count the number of times a correspondence occurs in each word in our list. If it is used more than once in a word, then it is counted for each occurrence.

Frequency (%) - The percentage of time that a phoneme is represented by a grapheme.

For weighted ranking:
We use two different word frequency lists to determine a word's frequency. First, we use a Project Gutenberg word frequency list from 2006 to get a baseline in written text. Since Project Gutenberg (PG) is limited to public domain books it does not have recent words like 'aliens' and 'radiation'. We used Open Subtitles, open source movie subtitles, as our second list since it includes recent movies and hence, modern words.

We multiply the Open Subtitles frequency by 4 to bring it in line with values from the Project Gutenberg frequencies and then average the two frequencies. We wanted common words like 'it' and 'that' to be roughly equivalent for both data sets.

Weighted Frequency (total) - We look at each word, then multiply the number of times a particular correspondence occurs in the word by the word's frequency, then we add all these values together for that correspondence.

Here's an example. This is the calculation for 'f' = /v/.
PG frequency for 'of': 33,950,064.00
Subtitle frequency for 'of': 1,847,884.00
Average frequency: (33,950,064.00 + (1,847,884.00 x 4)) / 2 = 20,670,800.00
Number of times 'f' = /v/ in the word 'of': 1
Weighted Frequency for 'f' = /v/ in the word 'of': 20,670,800.00 x 1 = 20,670,800.00

We repeat this calculation for the far less common word 'thereof' to get the weighted frequency of 15,143.25

Finally, we sum the weighted frequencies and divide by 5, the lowest frequency for all correspondences, to make the numbers more manageble.
Weighted Frequency (total): (20,670,800.00 + 15,143.25) / 5 = 4,137,188.65

Weighted Frequency (%): The percentage of time that when you come across that phoneme in text that it will be represented by that particular grapheme.

* These calculations are based on the count of phoneme-grapheme correspondences across 26,755 words as of August 2023.

Other References

For previous work in this area see Paul Hanna's paper Phoneme-Grapheme Correspondences as Cues to Spelling Improvement