I do know what I am talking about regarding cryptography, it is my job. Explain to me what is wrong with my explanation if you know it better.
Ok, answer the following for me:
1) Can you tell me the key length of the private key of a wallet?
2) Can you tell me who "chooses" the private key - the "wallet" or the user?
3) At which point does the redundancy of the language come into play - a) upon private key generation or b) when a user decides to encrypt his wallet with a password of his choosing?
4) After you have explained 1-3 can you explain the relevance of the users wallet password and redundancy of a language to the private key in the wallet and how you will derive the private key of the private/public key pair from the public key if you happen to obtain the users wallet password from a rainbow table of some sorts that you are referring to?
Sure I can:
1) The lenght is 256 bit or 32 bytes if you like
2) The input for the hash function that produces the private key can be from human input or from a (strong) random generator (that is built into the wallet)
3) If I understand this question right: In both situations
4) It is not about getting the users wallet password with a rainbow table. See answer 2 where it is possible to have human input (so called brain wallet) for the hash function that results in the private key. Also see the details of the sausage example.
It is only in the case of where a private key of a public/private key pair is a function of a human input, that the redundancy of the user's language could potentially cause a reduction of the key space. If you do the maths it is not feasible to create a rainbow table for 256bits and in addition there is not enough computing power in existence today to attempt that.