The present continuous tense is formed from the present tense of the verb be and the present participle (-ing form) of a verb:
Use
1. We use the present continuous tense to talk about the present:
for something that is happening at the moment of speaking:
I’m just leaving work. I’ll be home in an hour.
Please be quiet. The children are sleeping.
for something which is happening before and after a given time:
At eight o’clock we are usually having breakfast.
When I get home the children are doing their homework.