Daimon wrote:Was the semicolon remark a joke? I have to question whether or not I actually know how to use one if it was not.
Semi-colons are usually used to join two related sentences (and often conveniently allow you to omit 'implied' words that would be needed if the sentences were separated by a full stop). However, in this case the two sentences are only related in that they follow on from one another. You can replace the semi-colon there with a full stop without any loss of meaning. Since you think otherwise, however, it's likely that I have misinterpreted the meaning of the sentence/s; probably due to the fact that I don't have enough context!
Note that the following discussion about list etiquette is not related to the main topic of how to write effective run-on sentences, and whether or not the OP's sentence is one:
As for the, "and" I should have had, I did not include it because it was not the last item in my list; that item being "the general Illiteracy..."
Yes but all of those items don't follow on from 'its'. Here are the things (I think) you want to list, individually:
mistakes in its syntax
mistakes in its structure
mistakes in the general idea being expressed
mistakes in its spelling
mistakes in its word usage
the general Illiteracy it brings about by way of not being native in the language.
Some of those things don't start with "mistakes in its". One of them doesn't even start with 'mistakes'.
To see why the way you have done it is wrong, try rearranging the order of the items in the list:
... mistakes in its: the general illiteracy it brings about by way of not being native in the language, the general idea being expressed, spelling, word usage, syntax, and structure.