It seems like English is this person's second language and writing a blog is a good way to practice. However, there are quite a few spelling and grammar errors. I can really recommend "English Grammar in Use" by Raymond Murphy on the subject. It is impeccable until the intermediate level and "Essential Grammar in Use" is great for advanced speakers.
I don't know if you're a native speaker or not but for non-natives I think English Grammar In Use is great for initial study and then reference later. It covers almost all patterns that are actually used in English without getting stuck on old forms or giving overly strict rules that people don't actually follow.