Present continuous is used to describe an action which is in progress at this particular moment. We use present simple to talk about a period that's an action occurred in the past. Past simple talks about basic sequences of events first i did this then i did thisthen i did that then i did that for example all right so what i said was i lived in west london for a long time now we can note there that i'm using four with past simple and we know don't we that four is often used with another tense  which tense do we often use for with well you'll know it's present perfect.