The present continuous/it's also called present progressive. (At the moment , here and now + you can use it for picture descriptions.)
You should use the simple present tense when you are talking about something that is happening now.
'Now' talks about the present so it can only be used in the present tense.
To talk about something that is happening now.
It is past tense. example: here and then now and then
when your talking about now. for example, i amreading
We use the present tense to describe actions happening right now, habitual actions, general truths, and scheduled future events.
The present tense is now. The future tense is any time after now.
The present continuous tense is used to talk about an action that is happening now as well as actions that will happen in the future.
Because commands are given now - in the present.
To refer to actions that are happening now (at the present moment)
was is the past tense of am eg. 'I am' (now) but 'I was' (is past)
'Now' isn't a verb and so doesn't have any tenses.