Perhaps this is just one of those silly questions which might not even stir you into giving a sarcastic response.
Well, honestly, if it were so easy, I wouldn’t have started blogging in the first place. There are tens of thousands of blogs and websites tackling the difficult aspects of English. Why then this one? – WHY NOT?
Here is a pdf containing the top one thousand words that most matter for English. Why not open it and check how many of them you know the meaning and use of?
And here’s the document: