In Present perfect^x, Present continuous^x, Present progressive^x

Hi,I have been to China twice. - Past Participle. Used in several tenses, like the present perfect. Sometimes used as an adjective.Studying history is a good way to waste your time. - Gerund. A verb used as a noun.Call me later, I'm busy. I am burning a couple of grammar books. - Present...

In General, the Continuous tenses express actions that are/were "in progress" at a certain time, therefore they are also called "Progressive tenses". 1) Present Continuous or Present Progressive is used, when the action is happening just right now in this moment: "I'm answering your question...