Present Perfect + for & since

Use the present perfect + for(durante) & since(desde) to talk about actions and states wich started in the past and are still true now.

Where do you live now? In London.
How long have you lived there? I've lived there since 1990.

Where do you study? I study in the University.
How long have you studied there? I've studied there for three yers.

Use How long? to ask the questions about the duration of an action or a state.

Use SINCE with the beginning of a period of time.
Use FOR + a period of time.

!!!!!
You dan't use Present Simple here. How long do you live here? I live in London since 1980.