You have probably noticed by now that Present Continuous has a specific characteristic in that it allows us to talk about an extended period centred on the present. It effectively has the ability to stretch the Present so that our Reference Point (R) can be today, this week, this month, this year...even every day or all the time (or never!). Learning how to choose between a temporary present tense (Present Continuous) and a constant present tense (Present Simple) will give you a head start when communicating with native English speakers.
The Core Characteristics of the Present Continuous are concerned with expressing a temporary action, which can cover any amount of time, from right now to a period of years. In order to clarify the exact timeframe of the sentence, the speaker needs to provide extra information.
|I'm leaving the house|
For example, if I say, I'm leaving the house, and I don't add any further information,
The only way to have clarity on this is to know the context or to ask for more information. When are you leaving and why are you leaving?
In Locations in Time, you'll see that it is necessary to add information about time in order to avoid confusion unless the context of the conversation means that someone understands exactly what you mean without that information.