Here are some things that will help you a lot when trying to decrypt a substitution cipher.

Order Of Frequency Of Single Letters

E T A O I N S H R D L U


Order Of Frequency Of Digraphs

th er on an re he in ed nd ha at en es of or nt ea ti to it st io le is ou ar as de rt ve


Order Of Frequency Of Trigraphs

the and tha ent ion tio for nde has nce edt tis oft sth men


Order Of Frequency Of Most Common Doubles

ss ee tt ff ll mm oo


Order Of Frequency Of Initial Letters

T O A W B C D S F M R H I Y E G L N P U J K


Order Of Frequency Of Final Letters

E S T D N R Y F L O G H A K M P U W


One-Letter Words

a, I.


Most Frequent Two-Letter Words

of, to, in, it, is, be, as, at, so, we, he, by, or, on, do, if, me, my, up, an, go, no, us, am


Most Frequent Three-Letter Words

the, and, for, are, but, not, you, all, any, can, had, her, was, one, our, out, day, get, has, him, his, how, man, new, now, old, see, two, way, who, boy, did, its, let, put, say, she, too, use


Most Frequent Four-Letter Words

that, with, have, this, will, your, from, they, know, want, been, good, much, some, time