English is my first language - I wanted to say that right off the bat (immediately) and furthermore, I'm an American. That said, when I write, I like to use archaic language, obscure slang sayings and even translations of sayings or proverbs from other languages, whatever the character's individuality calls for and I can justify this because it is all potentially part of American English. We are a nation of immigrants and our speech reflects that, on the whole, if not in the microcosm. Many expressions are translations from a language other than English, especially slang terms.

A number of my personal speech patterns are based on the speech of the Smokey Mountains - West Virginia to be precise. These are not the ones prevalent in the mid-west, or in the cities and they can be typified as un-educated or ignorant because they are not "Standard English". But for me, Standard English is boring, banal and tasteless - like wall-paper paste. It's far more fun to say "Invisible insanity" than "Out of sight, out of mind" (and faster too). Or to "crack wise" than to be "wise-cracking".

My point is, for every person who complains about your "non-Standard" phrases, there are likely two or three others who find it colourful and exciting. Please, do not stop or feel self-conscious - write as the story and characters dictate. If not, you will be like the father in the Aesop story of the man, the boy and the mule, who tried to please everyone, ended up pleasing no one and lost the mule he was taking to market to boot (also).

Beannachd leat.