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I have a question which is somewhat similar to What are the most common consonants used in English? (on wikiHow). What are the most common seven letters that come second in pairs after consonants and seven ones after vowels?

For example, it might be something like this:

  • After consonants: E > R > A > I > O > U ...

  • After vowels: R > T > N > S ...

share|improve this question

closed as off topic by John Lawler, tchrist, Robusto, J.R., cornbread ninja 麵包忍者 Apr 8 '13 at 3:06

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I can correct your "informations": it should always be singular "information" no matter how much you have. –  Hugo Apr 5 '13 at 23:13
What is 'blending'? Like mixing? or putting one next to the other? –  Mitch Apr 6 '13 at 0:10
Does this fall under any of the categories of questions given in the FAQ? –  gmcgath Apr 6 '13 at 12:31

2 Answers 2

up vote 8 down vote accepted

Summary Answer

Here are the chances of each letter being followed by a vowel (defined to be [aeiouy]), a consonant, or a hyphen taking from the OED list described below, and with rounding:

a: C= 90%, V=  7%, -= 1%
b: C= 32%, V= 65%, -= 1%
c: C= 40%, V= 59%, -= 0%
d: C= 17%, V= 77%, -= 4%
e: C= 79%, V= 14%, -= 5%
f: C= 31%, V= 68%, -= 1%
g: C= 35%, V= 57%, -= 7%
h: C=  8%, V= 85%, -= 4%
i: C= 82%, V= 16%, -= 0%
j: C=  0%, V= 98%, -= 0%
k: C= 18%, V= 71%, -=10%
l: C= 26%, V= 74%, -= 2%
m: C= 14%, V= 83%, -= 1%
n: C= 49%, V= 47%, -= 3%
o: C= 79%, V= 15%, -= 3%
p: C= 43%, V= 57%, -= 2%
q: C=  0%, V=100%, -= 0%
r: C= 31%, V= 64%, -= 4%
s: C= 61%, V= 36%, -= 1%
t: C= 28%, V= 67%, -= 3%
u: C= 90%, V=  9%, -= 0%
v: C=  1%, V= 99%, -= 0%
w: C= 22%, V= 71%, -= 5%
x: C= 15%, V= 72%, -=11%
y: C= 58%, V= 24%, -=17%
z: C=  7%, V= 91%, -= 1%

You’ll get different answers if you run this algorithm on actual text, but running against a dictionary list (according to /usr/share/dict/words that is), the bigram frequency of English letters within individual words without regard to case is:

a: n=16.210% l=14.568% t=14.195% r=10.176% c=6.912% s=5.171% b=5.064% m=4.195% p=4.023% d=3.725% g=3.052% e=2.608% u=2.033% i=1.846% v=1.198% k=1.041% f=0.938% y=0.695% w=0.575% z=0.526% h=0.418% x=0.415% o=0.167% q=0.143% j=0.058% a=0.044% 
b: l=17.794% e=15.060% a=14.682% i=13.580% r=11.514% o=10.468% u=7.700% b=2.327% s=1.397% y=0.983% c=0.740% d=0.717% t=0.665% m=0.467% p=0.422% h=0.321% j=0.299% f=0.209% v=0.205% g=0.161% n=0.134% w=0.093% k=0.022% q=0.022% z=0.015% 
c: o=20.811% a=16.729% h=14.334% e=10.216% i=7.048% r=6.699% t=5.881% u=5.188% l=4.251% k=3.528% y=3.112% c=1.410% s=0.421% n=0.194% q=0.050% z=0.043% m=0.038% d=0.014% w=0.013% p=0.007% b=0.007% f=0.004% 
d: e=27.744% i=25.361% o=11.381% a=11.007% r=7.149% u=4.272% l=2.729% y=2.355% d=2.021% n=1.654% g=0.992% s=0.723% m=0.451% w=0.436% h=0.408% f=0.328% b=0.204% v=0.176% t=0.155% j=0.139% p=0.133% c=0.105% k=0.040% z=0.028% q=0.009% 
e: r=21.117% n=13.720% s=10.833% d=8.337% l=6.612% t=5.970% a=5.168% c=4.474% m=3.585% p=2.908% x=2.738% e=2.371% o=2.318% u=2.300% i=1.332% v=1.015% f=1.012% g=1.006% b=0.772% w=0.608% y=0.563% q=0.462% h=0.402% k=0.182% z=0.106% j=0.090% 
f: o=17.155% i=16.589% e=13.451% l=12.484% u=10.544% a=10.472% r=9.432% f=5.256% t=2.223% y=1.625% s=0.171% n=0.105% w=0.079% h=0.079% m=0.072% d=0.066% c=0.046% b=0.046% g=0.033% j=0.026% p=0.026% k=0.013% v=0.007% 
g: e=17.649% a=13.966% r=12.663% i=12.536% l=9.725% o=8.520% u=6.482% n=4.632% y=4.127% h=3.810% g=2.676% m=1.414% s=0.559% w=0.329% t=0.230% b=0.226% f=0.136% d=0.123% p=0.107% z=0.033% k=0.025% c=0.021% v=0.008% j=0.004% 
h: e=23.123% o=17.132% i=15.573% a=15.400% y=13.297% u=3.464% r=3.023% t=2.513% l=1.780% n=1.460% m=1.009% w=0.537% b=0.404% f=0.350% s=0.289% p=0.166% h=0.109% c=0.109% d=0.095% g=0.065% k=0.054% v=0.020% q=0.014% z=0.014% 
i: n=19.675% c=13.060% s=11.182% t=8.071% o=7.785% a=7.516% d=5.369% l=4.947% m=3.005% z=2.518% v=2.501% f=2.307% p=2.230% r=2.127% g=1.968% e=1.965% b=1.331% k=0.914% u=0.877% i=0.200% x=0.193% q=0.097% h=0.067% j=0.037% w=0.032% y=0.026% 
j: u=27.992% a=26.987% o=19.958% e=17.741% i=6.192% r=0.293% h=0.209% y=0.167% n=0.126% d=0.084% l=0.084% m=0.042% p=0.042% b=0.042% t=0.042% 
k: e=34.017% i=18.734% a=12.784% o=5.597% l=5.393% n=4.768% u=3.084% y=2.962% h=2.649% s=2.160% r=1.766% w=1.005% b=0.910% t=0.842% f=0.815% k=0.720% m=0.706% d=0.299% p=0.299% j=0.163% c=0.163% g=0.095% v=0.054% z=0.014% 
l: e=20.017% i=18.093% a=13.940% y=12.417% l=10.787% o=10.420% u=3.428% t=2.218% d=1.325% p=1.181% m=0.950% v=0.935% c=0.858% s=0.675% n=0.631% f=0.560% k=0.461% g=0.448% b=0.293% w=0.148% h=0.105% r=0.079% z=0.021% x=0.003% j=0.003% q=0.003% 
m: a=22.239% e=19.785% i=19.341% o=15.400% p=5.855% u=4.606% y=3.800% b=3.623% m=2.911% n=1.174% s=0.316% l=0.271% f=0.185% r=0.091% d=0.070% w=0.068% c=0.063% t=0.055% h=0.050% v=0.034% k=0.026% g=0.021% j=0.008% z=0.008% q=0.003% 
n: e=17.225% t=12.959% o=12.242% i=11.314% g=10.255% a=9.098% d=6.285% c=5.591% s=3.606% n=2.071% u=2.024% y=1.072% f=0.998% k=0.951% v=0.638% l=0.621% p=0.511% r=0.486% m=0.394% z=0.391% h=0.318% b=0.290% j=0.242% w=0.230% q=0.127% x=0.062% 
o: n=15.524% r=11.107% u=7.706% p=7.613% s=6.841% m=6.823% l=6.395% t=6.010% c=5.344% g=4.665% v=3.711% d=3.530% i=2.467% o=2.323% b=2.121% w=1.757% a=1.267% f=1.065% e=0.954% x=0.869% k=0.729% h=0.389% y=0.302% z=0.286% q=0.134% j=0.072% 
p: r=16.661% e=15.491% h=15.215% a=12.458% o=11.376% i=7.165% l=6.448% t=3.589% u=3.528% s=3.152% y=2.008% p=1.901% n=0.590% m=0.117% w=0.079% f=0.075% b=0.044% c=0.040% k=0.030% g=0.018% d=0.008% j=0.002% v=0.002% q=0.002% 
q: u=99.635% e=0.091% o=0.091% a=0.046% r=0.046% q=0.046% i=0.046% 
r: e=17.368% a=14.913% i=14.802% o=12.431% t=4.222% y=3.883% m=3.838% s=3.063% c=3.007% d=2.979% r=2.956% u=2.656% n=2.234% p=2.145% b=1.610% g=1.527% h=1.398% l=1.321% v=1.074% k=1.002% f=0.820% w=0.493% j=0.100% q=0.091% z=0.059% x=0.007% 
s: t=19.285% s=10.149% e=9.633% i=9.576% u=7.644% c=6.541% h=6.366% p=5.951% a=5.921% o=5.063% m=4.181% l=2.188% y=1.958% n=1.448% k=1.097% w=0.984% q=0.801% f=0.308% b=0.230% r=0.184% g=0.179% d=0.159% v=0.094% j=0.049% z=0.011% 
t: e=21.499% i=21.350% r=12.072% a=10.525% o=10.266% h=9.607% y=3.576% u=3.410% t=2.402% l=1.364% c=0.847% w=0.699% s=0.650% m=0.337% f=0.334% n=0.292% b=0.236% p=0.144% g=0.108% z=0.102% d=0.070% k=0.038% v=0.033% j=0.028% q=0.012% 
u: n=37.203% s=15.536% l=9.359% r=9.257% m=5.863% t=4.438% c=2.816% i=2.544% a=2.395% p=2.229% e=2.100% d=1.624% g=1.367% b=1.263% o=0.598% f=0.379% v=0.299% k=0.224% x=0.217% z=0.080% y=0.066% j=0.038% h=0.038% q=0.027% u=0.024% w=0.016% 
v: e=45.838% i=24.611% a=18.107% o=9.087% u=1.744% y=0.302% r=0.123% v=0.066% l=0.038% s=0.028% c=0.019% k=0.019% n=0.009% g=0.009% 
w: a=23.647% i=16.779% o=16.412% e=14.446% h=9.947% r=4.216% n=3.979% l=2.084% s=1.445% d=1.149% k=0.853% y=0.817% b=0.805% t=0.663% u=0.604% m=0.568% f=0.462% w=0.343% p=0.343% c=0.237% g=0.154% q=0.024% v=0.012% z=0.012% 
x: i=29.700% a=18.094% e=12.050% y=9.937% o=9.714% t=9.232% u=2.744% c=2.225% p=2.113% l=0.853% b=0.667% h=0.519% w=0.445% f=0.445% m=0.408% s=0.222% d=0.148% g=0.148% n=0.148% q=0.111% r=0.037% k=0.037% 
y: l=15.983% s=10.095% t=8.919% a=8.022% c=7.723% p=7.239% m=6.135% o=6.094% n=5.042% e=4.733% r=4.228% i=3.702% g=2.506% d=2.475% w=1.464% b=1.433% h=1.072% u=0.949% f=0.897% z=0.557% x=0.474% k=0.155% q=0.041% y=0.031% v=0.031% 
z: e=41.064% a=18.986% o=17.462% i=9.072% y=5.798% z=4.093% u=1.160% l=1.046% w=0.205% d=0.205% r=0.114% m=0.114% c=0.114% h=0.091% k=0.091% s=0.091% n=0.068% g=0.045% t=0.045% p=0.045% b=0.045% f=0.023% v=0.023% 

The simple little program that generates that table is this:

# letter_bigrams - show following-letter frequencies
# Tom Christiansen <tchrist@perl.com>
# Fri Apr  5 17:49:49 MDT 2013

use strict;
use warnings;
use List::Util qw(sum);

my %after;

while (<>) {
    while ( /(.)(.)/g ) {
        $after{lc $1}{lc $2}++;

for my $this (sort keys %after) {
    print "$this: ";
    my $total = sum  values %{ $after{$this} };
    for my $that (sort { $after{$this}{$b} <=> $after{$this}{$a} } keys %{ $after{$this} } ) {
        my $chance = $after{$this}{$that} / $total;
        printf "%s=%.3f%% ", $that, 100 * $chance;
    print "\n";

Run it on your own data for different corpus results.


Run against the OED 2E word list, plus quarterly supplements, and only on non-obsolete things (no dagger of death) that are purely alphabetic with optional hyphens, not multiword phrases, yields this list:

-: s=11.209% b=10.862% c=8.537% p=7.660% f=5.864% t=5.770% h=5.521% w=5.462% m=5.292% l=4.818% r=4.658% d=4.121% a=3.614% g=3.496% e=3.156% o=2.453% i=1.819% n=1.599% k=0.988% v=0.847% j=0.785% u=0.752% y=0.396% q=0.203% z=0.075% à=0.016% ā=0.010% þ=0.007% x=0.003% ȝ=0.003% ê=0
a: n=15.442% t=14.988% l=13.594% r=10.348% c=6.188% s=5.542% b=4.589% d=4.283% m=4.012% p=3.972% g=3.237% i=2.717% u=1.731% v=1.357% -=1.345% y=1.114% f=1.106% k=1.097% e=1.061% w=0.771% z=0.434% x=0.408% h=0.330% q=0.112% o=0.076% a=0.065% j=0.055% ï=0.008% î=0.004% ð=0.003% ȝ
=0.003% ñ=0.003% ë=0.002% ç=0.002% þ=0.001% 
á: n=42.857% p=28.571% i=14.286% t=14.286% 
à: -=100.000% 
â: t=72.727% n=18.182% s=9.091% 
å: l=100.000% 
ä: r=26.316% t=21.053% g=15.789% n=10.526% u=10.526% s=5.263% h=5.263% b=5.263% 
ã: o=100.000% 
ā: r=33.333% d=33.333% t=33.333% 
æ: l=100.000% 
b: l=15.999% e=14.986% a=14.128% i=12.834% o=12.807% r=11.750% u=8.629% b=2.876% -=1.363% s=1.164% y=1.133% t=0.491% d=0.333% m=0.299% j=0.278% c=0.254% h=0.117% v=0.103% f=0.079% n=0.079% g=0.076% p=0.065% w=0.041% é=0.027% k=0.017% z=0.014% â=0.014% ê=0.007% x=0.007% œ=0.007%
 ú=0.003% ü=0.003% ā=0.003% ō=0.003% ö=0.003% ó=0.003% ø=0.003% 
c: o=21.026% a=15.262% h=14.436% e=8.853% r=7.213% i=6.691% k=6.537% t=5.631% u=4.967% l=4.962% y=2.452% c=1.081% s=0.423% n=0.174% -=0.136% q=0.041% m=0.021% z=0.021% d=0.019% é=0.014% w=0.010% b=0.009% f=0.007% è=0.003% p=0.003% ú=0.002% j=0.002% œ=0.002% ô=0.002% 
č: e=100.000% 
ç: a=56.250% o=37.500% u=6.250% 
d: e=27.836% i=24.914% o=10.298% a=7.791% r=7.008% -=4.385% u=4.330% d=2.939% l=2.621% y=2.231% g=1.646% n=1.419% s=0.662% w=0.384% m=0.264% h=0.255% f=0.244% é=0.129% t=0.126% j=0.092% v=0.092% c=0.080% b=0.075% p=0.066% k=0.057% z=0.037% ā=0.006% ú=0.006% è=0.003% ä=0.003% 
ð: e=42.857% l=28.571% ð=14.286% s=14.286% 
e: r=20.881% n=11.875% d=11.423% s=9.384% l=6.221% t=5.636% -=4.989% a=4.926% c=3.694% e=3.370% m=3.081% x=2.392% p=1.989% o=1.733% u=1.610% i=1.115% v=0.982% y=0.976% g=0.929% f=0.853% w=0.489% b=0.470% q=0.383% h=0.206% k=0.195% z=0.109% j=0.062% ñ=0.009% ð=0.005% ȝ=0.004% ï=
0.004% þ=0.002% ö=0.001% 
é: e=26.230% t=12.295% c=12.295% r=7.377% l=6.557% p=6.557% m=4.098% d=3.279% g=3.279% n=3.279% v=3.279% b=3.279% i=2.459% s=2.459% a=0.820% f=0.820% q=0.820% o=0.820% 
è: r=62.963% s=9.259% g=9.259% v=5.556% c=5.556% m=3.704% n=1.852% q=1.852% 
ê: p=38.889% t=38.889% l=5.556% c=5.556% n=5.556% m=5.556% 
ě: t=100.000% 
ë: n=20.000% p=20.000% r=10.000% d=10.000% m=10.000% l=10.000% -=10.000% t=10.000% 
f: i=17.313% o=15.660% l=13.093% e=12.618% a=11.001% u=9.081% r=9.071% f=5.650% t=2.815% y=1.567% -=1.415% s=0.212% n=0.101% m=0.061% é=0.056% k=0.045% d=0.040% w=0.035% c=0.035% p=0.030% ê=0.025% ü=0.020% h=0.020% v=0.010% è=0.005% j=0.005% g=0.005% ö=0.005% z=0.005% 
g: e=16.087% r=13.093% a=12.605% i=10.376% l=8.847% o=7.912% -=6.871% u=6.533% h=5.280% n=3.922% g=3.154% y=3.123% m=0.952% s=0.464% t=0.191% w=0.143% f=0.113% d=0.092% b=0.068% p=0.051% é=0.031% z=0.027% k=0.010% c=0.010% ö=0.010% ü=0.007% ê=0.007% j=0.003% v=0.003% ā=0.003% þ
=0.003% â=0.003% 
h: e=22.371% o=18.586% a=16.110% i=15.274% y=9.293% -=4.388% u=3.530% t=2.745% r=2.489% l=1.468% n=1.312% m=0.906% w=0.389% f=0.287% s=0.252% b=0.137% p=0.096% d=0.073% c=0.070% k=0.048% é=0.038% h=0.032% q=0.029% g=0.016% v=0.016% ü=0.013% ä=0.010% è=0.006% j=0.003% z=0.003% ö
=0.003% á=0.003% â=0.003% 
i: n=25.113% c=11.855% s=10.053% t=8.094% o=6.724% a=5.667% l=5.322% d=3.761% z=3.115% m=2.974% r=2.495% v=2.467% p=2.420% e=2.412% f=2.396% g=2.071% b=1.084% u=0.575% k=0.532% -=0.351% x=0.204% q=0.106% h=0.057% i=0.054% w=0.033% j=0.022% è=0.019% y=0.015% é=0.004% ð=0.001% ä=
0.001% ȝ=0.001% ö=0.001% þ=0.001% 
í: a=100.000% 
î: t=100.000% 
ï: v=26.316% d=26.316% n=15.789% q=10.526% f=10.526% s=5.263% t=5.263% 
j: u=27.257% a=25.239% o=23.324% e=16.005% i=7.079% -=0.171% n=0.171% h=0.137% r=0.103% p=0.103% ō=0.068% m=0.068% ū=0.034% d=0.034% y=0.034% ä=0.034% t=0.034% s=0.034% l=0.034% c=0.034% 
k: e=32.319% i=20.563% -=10.302% a=9.602% n=6.453% l=5.073% o=3.535% y=2.479% u=2.207% s=1.642% h=1.548% r=1.203% t=0.586% w=0.533% f=0.460% k=0.377% m=0.282% b=0.220% d=0.105% p=0.105% g=0.094% v=0.094% j=0.042% ü=0.042% c=0.042% ä=0.021% ë=0.021% é=0.021% á=0.021% ō=0.010% 
l: e=20.132% i=16.672% l=13.454% a=12.543% y=10.748% o=10.036% u=2.958% t=2.687% d=1.645% f=1.595% -=1.533% v=0.893% m=0.886% p=0.795% k=0.762% c=0.694% s=0.625% n=0.486% g=0.353% b=0.204% w=0.073% h=0.067% r=0.062% é=0.032% z=0.018% q=0.010% j=0.007% ö=0.007% ä=0.006% x=0.006%
 ü=0.001% è=0.001% å=0.001% ó=0.001% â=0.001% ø=0.001% 
ʟ: -=100.000% 
m: a=21.319% e=19.383% i=17.979% o=16.017% p=6.198% u=5.766% b=3.997% m=3.259% y=2.615% -=1.104% n=0.884% s=0.474% l=0.224% f=0.175% c=0.094% r=0.078% é=0.075% d=0.052% t=0.042% v=0.042% h=0.042% k=0.031% w=0.028% g=0.024% z=0.019% ü=0.017% ä=0.009% â=0.009% j=0.007% q=0.007% ō
=0.007% ê=0.005% ö=0.005% x=0.002% è=0.002% å=0.002% œ=0.002% ô=0.002% 
n: g=17.044% e=16.932% t=11.740% i=10.645% o=7.999% a=7.603% d=7.468% c=4.689% -=3.491% s=2.916% n=2.192% u=1.869% k=1.365% y=0.950% f=0.714% v=0.508% l=0.456% h=0.227% z=0.200% j=0.189% m=0.143% r=0.131% b=0.115% q=0.111% p=0.090% w=0.089% x=0.064% é=0.043% œ=0.003% ê=0.001% ä
=0.001% ē=0.001% ā=0.001% č=0.001% è=0.001% ç=0.001% ó=0.001% á=0.001% 
ñ: o=55.556% a=36.111% i=5.556% e=2.778% 
o: n=15.074% r=10.786% u=8.005% l=6.502% p=6.473% t=6.376% s=6.087% m=5.730% c=4.721% g=4.390% d=3.208% o=3.083% v=3.022% w=2.679% -=2.650% i=2.345% b=2.036% a=1.459% f=1.224% k=1.179% e=0.931% x=0.899% y=0.421% z=0.268% h=0.259% q=0.104% j=0.059% ȝ=0.011% ï=0.005% û=0.004% ö=0
.004% ë=0.001% î=0.001% ñ=0.001% 
ó: n=50.000% t=50.000% 
ô: t=80.000% s=20.000% 
ö: g=19.231% d=15.385% t=15.385% n=11.538% r=7.692% p=7.692% h=7.692% s=3.846% c=3.846% k=3.846% b=3.846% 
ø: r=50.000% d=50.000% 
ō: -=100.000% 
œ: u=50.000% i=37.500% n=12.500% 
p: e=15.495% r=13.602% a=13.131% o=12.909% h=12.125% i=8.869% l=7.397% u=4.210% t=2.817% p=2.640% s=2.575% y=1.716% -=1.617% n=0.510% f=0.086% m=0.062% k=0.043% é=0.037% c=0.034% w=0.028% d=0.022% g=0.021% b=0.021% v=0.007% â=0.007% ü=0.004% ī=0.004% j=0.002% ê=0.002% ä=0.002% 
x=0.002% è=0.002% á=0.002% 
0.515% -=0.277% w=0.119% s=0.119% v=0.079% c=0.079% b=0.079% e=0.040% û=0.040% y=0.040% p=0.040% q=0.040% 
r: e=18.587% a=13.992% i=13.720% o=11.273% t=4.268% -=3.847% y=3.359% m=3.332% d=3.228% s=2.920% r=2.829% u=2.702% n=2.652% c=2.505% p=1.797% g=1.480% k=1.397% b=1.351% l=1.351% v=1.069% h=0.992% f=0.766% w=0.287% q=0.066% j=0.063% z=0.062% é=0.055% x=0.021% ö=0.007% ü=0.002% è
=0.002% ȝ=0.002% ç=0.002% á=0.002% ê=0.001% ē=0.001% ā=0.001% ō=0.001% þ=0.001% ô=0.001% â=0.001% ø=0.001% 
s: t=20.016% e=10.589% s=9.549% h=8.292% i=8.097% c=6.251% p=5.786% a=5.411% u=5.375% o=4.897% m=3.969% l=2.369% y=1.752% n=1.557% k=1.377% w=1.345% -=1.227% q=0.835% f=0.336% b=0.229% d=0.185% g=0.170% r=0.163% v=0.108% j=0.054% é=0.035% z=0.017% è=0.004% œ=0.002% ä=0.001% ö=0
.001% û=0.001% 
š: t=100.000% 
t: e=21.455% i=19.281% r=11.954% a=9.735% o=9.623% h=8.924% u=3.687% y=3.420% t=3.387% -=3.157% l=1.392% c=1.265% w=0.756% s=0.670% n=0.289% f=0.254% m=0.206% z=0.126% b=0.091% g=0.074% p=0.057% d=0.054% é=0.033% j=0.030% v=0.027% k=0.024% q=0.008% ê=0.005% ä=0.005% ë=0.004% è=
0.002% à=0.002% ü=0.001% ī=0.001% ā=0.001% ö=0.001% â=0.001% 
u: n=30.837% s=14.063% r=11.030% l=9.468% m=6.208% t=5.677% c=3.315% e=2.898% i=2.775% p=2.758% a=2.422% g=2.313% d=1.922% b=1.771% f=0.587% o=0.575% v=0.315% x=0.258% k=0.246% -=0.135% z=0.085% y=0.073% h=0.066% j=0.057% é=0.040% q=0.033% w=0.028% u=0.024% í=0.005% ñ=0.005% ġ=
0.002% ë=0.002% è=0.002% ç=0.002% 
ú: n=100.000% 
û: t=100.000% 
ü: b=30.000% n=20.000% y=15.000% c=15.000% h=15.000% g=5.000% 
ū: s=100.000% 
v: e=46.063% i=25.395% a=15.766% o=9.234% u=1.503% y=0.504% r=0.495% v=0.185% l=0.176% -=0.134% s=0.092% é=0.059% ö=0.050% t=0.042% c=0.042% d=0.034% h=0.034% á=0.034% n=0.025% k=0.017% ê=0.017% œ=0.017% p=0.017% w=0.008% j=0.008% è=0.008% ṛ=0.008% g=0.008% ä=0.008% f=0.008% q=
w: a=23.422% e=17.959% i=14.670% o=14.102% h=9.502% -=5.418% n=4.077% r=3.327% l=1.629% d=1.197% s=1.175% k=0.803% y=0.561% t=0.439% b=0.303% u=0.296% f=0.296% m=0.235% p=0.182% g=0.136% w=0.114% c=0.076% ü=0.038% ö=0.015% z=0.015% v=0.008% q=0.008% 
x: i=25.909% a=15.985% e=12.273% -=11.136% t=9.015% o=8.030% y=6.894% u=2.917% p=2.273% c=1.780% l=0.720% m=0.606% h=0.417% w=0.379% f=0.341% s=0.341% d=0.303% n=0.152% b=0.152% v=0.114% é=0.114% x=0.076% g=0.076% 
y: -=17.449% l=11.059% s=9.051% c=7.035% t=6.381% a=6.220% e=6.164% i=5.813% p=5.103% o=5.065% m=4.715% n=3.522% r=2.992% g=1.922% d=1.903% b=1.023% u=0.994% w=0.985% f=0.871% h=0.720% k=0.303% x=0.237% z=0.170% v=0.057% q=0.057% ȝ=0.038% þ=0.038% j=0.028% ü=0.028% ū=0.019% y=0
.019% é=0.019% 
ȝ: e=60.000% t=10.000% n=6.667% c=6.667% h=6.667% i=6.667% l=3.333% 
z: e=43.890% a=16.577% i=13.647% o=11.122% z=6.149% y=4.106% l=1.330% u=1.214% -=0.617% h=0.212% w=0.173% d=0.173% s=0.135% k=0.116% b=0.116% g=0.077% m=0.077% p=0.077% r=0.058% n=0.039% c=0.039% f=0.019% ö=0.019% q=0.019% 
þ: e=80.000% þ=10.000% o=10.000% 
ʿ: a=50.000% ī=50.000% 
ψ: -=100.000% 

The program was very, very slightly modified to handle Unicode this way, and it does assume input in Normalization Form C (NFC):

# letter_bigrams - show following-letter frequencies
# Tom Christiansen <tchrist@perl.com>
# Fri Apr  5 17:59:42 MDT 2013

use strict;
use warnings;
use open qw(:std :utf8);
use List::Util qw(sum);

use Unicode::Collate;

my $collator = new Unicode::Collate;    
my %after;

while (<>) {
    while ( /(.)(.)/g ) {
        $after{lc $1}{lc $2}++;

for my $this ($collator->sort(keys %after)) {
    print "$this: ";
    my $total = sum  values %{ $after{$this} };
    for my $that (sort { $after{$this}{$b} <=> $after{$this}{$a} } keys %{ $after{$this} } ) {
        my $chance = $after{$this}{$that} / $total; 
        printf "%s=%.3f%% ", $that, 100 * $chance;
    print "\n";


Weeding out the non-(A–Z) letters and deleting diacritics, than rounding and sorting by letter, the two sets come out like this, where set 1 represents /usr/shared/dict/words and set 2 represents (a reasonable subset of) the OED word list.

So a row labelled “1a” is the chance of those letters following a in the normal look(1) word list, and the following row “2a” immediately below it represents the chance of each of those letters following a in the OED word list.

Notice how even with rounding, you get somewhat different figures, which is rather interesting.

1a: n=16% l=15% t=14% r=10% c=7% s=5% b=5% m=4% p=4% d=4% g=3% e=3% u=2% i=2% v=1% k=1% f=1% y=1% w=1% z=1%
2a: n=15% t=15% l=14% r=10% c=6% s=6% b=5% d=4% m=4% p=4% g=3% i=3% u=2% v=1% -=1% y=1% f=1% k=1% e=1% w=1%
1b: l=18% e=15% a=15% i=14% r=12% o=10% u=8% b=2% s=1% y=1% c=1% d=1% t=1%
2b: l=16% e=15% a=14% i=13% o=13% r=12% u=9% b=3% -=1% s=1% y=1%
1c: o=21% a=17% h=14% e=10% i=7% r=7% t=6% u=5% l=4% k=4% y=3% c=1%
2c: o=21% a=15% h=14% e=9% r=7% i=7% k=7% t=6% u=5% l=5% y=2% c=1%
1d: e=28% i=25% o=11% a=11% r=7% u=4% l=3% y=2% d=2% n=2% g=1% s=1%
2d: e=28% i=25% o=10% a=8% r=7% -=4% u=4% d=3% l=3% y=2% g=2% n=1% s=1%
1e: r=21% n=14% s=11% d=8% l=7% t=6% a=5% c=4% m=4% p=3% x=3% e=2% o=2% u=2% i=1% v=1% f=1% g=1% b=1% w=1% y=1%
2e: r=21% n=12% d=11% s=9% l=6% t=6% -=5% a=5% c=4% e=3% m=3% x=2% p=2% o=2% u=2% i=1% v=1% y=1% g=1% f=1%
1f: o=17% i=17% e=13% l=12% u=11% a=10% r=9% f=5% t=2% y=2%
2f: i=17% o=16% l=13% e=13% a=11% u=9% r=9% f=6% t=3% y=2% -=1%
1g: e=18% a=14% r=13% i=13% l=10% o=9% u=6% n=5% y=4% h=4% g=3% m=1% s=1%
2g: e=16% r=13% a=13% i=10% l=9% o=8% -=7% u=7% h=5% n=4% g=3% y=3% m=1%
1h: e=23% o=17% i=16% a=15% y=13% u=3% r=3% t=3% l=2% n=1% m=1% w=1%
2h: e=22% o=19% a=16% i=15% y=9% -=4% u=4% t=3% r=2% l=1% n=1% m=1%
1i: n=20% c=13% s=11% t=8% o=8% a=8% d=5% l=5% m=3% z=3% v=3% f=2% p=2% r=2% g=2% e=2% b=1% k=1% u=1%
2i: n=25% c=12% s=10% t=8% o=7% a=6% l=5% d=4% z=3% m=3% r=2% v=2% e=2% p=2% f=2% g=2% b=1% u=1% k=1%
1j: u=28% a=27% o=20% e=18% i=6%
2j: u=27% a=25% o=23% e=16% i=7%
1k: e=34% i=19% a=13% o=6% l=5% n=5% u=3% y=3% h=3% s=2% r=2% w=1% b=1% t=1% f=1% k=1% m=1%
2k: e=32% i=21% -=10% a=10% n=6% l=5% o=4% y=2% u=2% s=2% h=2% r=1% t=1% w=1%
1l: e=20% i=18% a=14% y=12% l=11% o=10% u=3% t=2% d=1% p=1% m=1% v=1% c=1% s=1% n=1% f=1%
2l: e=20% i=17% l=13% a=13% y=11% o=10% u=3% t=3% d=2% f=2% -=2% v=1% m=1% p=1% k=1% c=1% s=1%
1m: a=22% e=20% i=19% o=15% p=6% u=5% y=4% b=4% m=3% n=1%
2m: a=21% e=19% i=18% o=16% p=6% u=6% b=4% m=3% y=3% -=1% n=1%
1n: e=17% t=13% o=12% i=11% g=10% a=9% d=6% c=6% s=4% n=2% u=2% y=1% f=1% k=1% v=1% l=1% p=1%
2n: g=17% e=17% t=12% i=11% o=8% a=8% d=7% c=5% -=3% s=3% n=2% u=2% k=1% y=1% f=1% v=1%
1o: n=16% r=11% u=8% p=8% s=7% m=7% l=6% t=6% c=5% g=5% v=4% d=4% i=2% o=2% b=2% w=2% a=1% f=1% e=1% x=1% k=1%
2o: n=15% r=11% u=8% l=6% p=6% t=6% s=6% m=6% c=5% g=4% d=3% o=3% v=3% w=3% -=3% i=2% b=2% a=1% f=1% k=1% e=1% x=1%
1p: r=17% e=15% h=15% a=12% o=11% i=7% l=6% t=4% u=4% s=3% y=2% p=2% n=1%
2p: e=16% r=14% a=13% o=13% h=12% i=9% l=7% u=4% t=3% p=3% s=3% y=2% -=2% n=1%
1q: u=100%
2q: u=98% i=1% a=1%
1r: e=17% a=15% i=15% o=12% t=4% y=4% m=4% s=3% c=3% d=3% r=3% u=3% n=2% p=2% b=2% g=2% h=1% l=1% v=1% k=1% f=1%
2r: e=19% a=14% i=14% o=11% t=4% -=4% y=3% m=3% d=3% s=3% r=3% u=3% n=3% c=3% p=2% g=1% k=1% l=1% b=1% v=1% h=1% f=1%
1s: t=19% s=10% e=10% i=10% u=8% c=7% h=6% p=6% a=6% o=5% m=4% l=2% y=2% n=1% k=1% w=1% q=1%
2s: t=20% e=11% s=10% h=8% i=8% c=6% p=6% a=5% u=5% o=5% m=4% l=2% y=2% n=2% k=1% w=1% -=1% q=1%
1t: e=21% i=21% r=12% a=11% o=10% h=10% y=4% u=3% t=2% l=1% c=1% w=1% s=1%
2t: e=21% i=19% r=12% a=10% o=10% h=9% u=4% y=3% t=3% -=3% l=1% c=1% w=1% s=1%
1u: n=37% s=16% l=9% r=9% m=6% t=4% c=3% i=3% a=2% p=2% e=2% d=2% g=1% b=1% o=1%
2u: n=31% s=14% r=11% l=9% m=6% t=6% c=3% e=3% i=3% p=3% a=2% g=2% d=2% b=2% f=1% o=1%
1v: e=46% i=25% a=18% o=9% u=2%
2v: e=46% i=25% a=16% o=9% u=2% r=1% y=1%
1w: a=24% i=17% o=16% e=14% h=10% r=4% n=4% l=2% s=1% d=1% k=1% y=1% b=1% t=1% u=1% m=1%
2w: a=23% e=18% i=15% o=14% h=10% -=5% n=4% r=3% l=2% d=1% s=1% k=1% y=1%
1x: i=30% a=18% e=12% y=10% o=10% t=9% u=3% c=2% p=2% l=1% b=1% h=1%
2x: i=26% a=16% e=12% -=11% t=9% o=8% y=7% u=3% p=2% c=2% l=1% m=1%
1y: l=16% s=10% t=9% a=8% c=8% p=7% m=6% o=6% n=5% e=5% r=4% i=4% g=3% d=2% w=1% b=1% h=1% u=1% f=1% z=1%
2y: -=17% l=11% s=9% c=7% t=6% a=6% e=6% i=6% p=5% o=5% m=5% n=4% r=3% g=2% d=2% u=1% b=1% w=1% f=1% h=1%
1z: e=41% a=19% o=17% i=9% y=6% z=4% u=1% l=1%
2z: e=44% a=17% i=14% o=11% z=6% y=4% l=1% u=1% -=1%
share|improve this answer
Very good! Obviously some letters are not always vowels or consonants, but assuming they were, can you summarise the most popular letters after vowels, and after consonants, like in the question? –  Hugo Apr 5 '13 at 23:59
@Hugo I thought of that, but I think it doesn’t make sense. Imagine a reduced universe of two consonants, Q and T, where Q is followed by U 100% of the time and T is followed by E and I each 40% of the time and by R the remaining 20% of the time. If you average those two together, you suddenly have all consonants in your universe followed by U 50% of the time. That does not seem sensible to me. –  tchrist Apr 6 '13 at 0:04
@Hugo Ok, I’ve reneged and put summary vowel-vs-consonant data at the top. Note that I’ve defined y to be a vowel for these purposes. –  tchrist Apr 6 '13 at 0:26
Future Wheel of Fortune contestants would do well to study this data. Nice work! –  J.R. Apr 6 '13 at 1:10

This site for solving cryptograms says:

Now try to identify some letters in the cryptogram, and from these, go on to whole words. This usually takes trial and error, but here are some tips:

  1. When two consonants start a word, the second is often H, L, or R. You can distinguish H from the other two because it very rarely appears after a vowel and very often before one; L and R appear freely both before and after vowels.

  2. A consonant that often follows a vowel but seldom precedes one is often N.

  3. A vowel frequently found in third-to-last position is often I, as in -ing, -ion, -ive, and other endings.

  4. Consonants that end several words may be D, S, or T.

  5. Three consonants together at the end of a word may be -ght or -tch. Four consonants may be -ghts.

  6. Look for words that may represent the prepositions above, after, amid(st), among (st), behind, beyond, from, over, upon, into, or with. It's very difficult to construct a message that avoids all prepositions.

  7. Look for prefixes like ex-, over-, un-, or up-.

  8. Look for suffixes like -ed, -er, -man or -men, or -ful.

  9. A low-frequency letter at the end of words may be Y.

  10. The lowest-frequency letter among the assumed vowels may be Y, as in sylph, nymph, lymph, hymn, myth, lynx, or pachyderm.

  11. When you make a guess at one word, try out those letters in other words of the crypt. Once you have two words right, the rest of the crypt usually comes easily. Remember, keep guessing! What one mind can devise, another mind can decode.

share|improve this answer
Very Thanks! Both answers are exactly what I need. I wish can accept both. –  iSang Apr 6 '13 at 2:11

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