> hanashikotoba or teineigo or most likely the mixture of both which is pretty odd.
Since that has been brought up I would like to ask for clarification on something since you seem to know the subject well.
I have guessed by myself from reading Japanese that these two forms are commonly mixed within sentences, but it depends whether the expression is... facing towards the other party, or internal.
For example, 「彼は来ると思います。」
And I think, 「彼が来るのはずっと待っていました。」
Is this correct?
Then, what did you mean by a mixture? Ending a sentence with ~masu one minute, and then plainly the next?
That would be weird in a conversation I guess, but I seem to remember seeing it in internet posts and such, perhaps to make a single sentence a bit more polite, often at the end of a post... I don't know.