I read your original sentence and thought that there was nothing more wrong with it than a basic typing mistake, and forums posts/text messages have lots of those. Indeed, I've seen many of those in forum posts from native English speakers, as well as having made many of those typing mistakes myself; so please don't need to beat your self up about it. What's your native language?
Since you asked for the corrections to improve your English the original sentence you and dagwit were discussing, I'll give you some pointers.
The original sentence was...
With a couple of minor corrections that becomes:
It is not semantics, it's that you don't know the meaning of the word "announcement."
At the start, the second word of the sentence "Is" should only have a lower case "i" not a capital letter. Capital letters mid sentence are for the word I or proper nouns like "English" or "Monday", every other word in the middle of a sentence states with a lower case letter. After the first word instance of the word semantics, I changed the word "Is" to "it's" removing the capitalisation of the letter I and changing the word from "is" to "it's". Generally speaking, if you start a sentence or resume after the pause indicated by a comma with the word "is", it means that what is going to come next is a question. For example:
I've made a few corrections to some of your sentences, is that OK with you?
Do you see how the position of the word "is" leads what comes next to being a question?
Like I say matey, it's minor corrections