I tell you earnestly, you must get into the habit of looking intensely at words,and assuring yourself of their meaning,syllable by syllable, nay, letter by letter.
You might read all the books in the National, if you could live long enough, and remain an utterly illiterate,uneducated person; but if you read ten pages of a good book, letter by letter...that is to say, with real accuracy...you are forevermore, in some measure, an educated person.
The entire difference between education and non-education (as regards the merely intellectual part of it) consists in this accuracy. A well-educated gentleman may not know many languages, may not be able to speak any but his own, may have read very few books; but whatever word he pronounces, he pronounces rightly.
An ordinarily clever and sensible seaman will be able to make his way ashore at most ports; yet he has only to speak a sentence to be known for an illiterate person; so also the accent, or turn of expression of a single sentence, will at once mark a scholar.
Let the accent of words be watched, and closely; let their meaning be watched more closely still. A few words, well chosen, will do the work that a thousand cannot do, when every one of those few is acting properly, in the function of one another.
So, what I'm trying to conceive here is that no matter what slang and accent you have and practice now...just let it be...as long as you feel comfort with it and people can understand you well...even if you are more American than American.