In some dictionary, I have read this example: "The amount of homework and other things he had going on was stressful."
My question is about 'going on', what is it? and what does it mean?
Thank you in advance.
To go on is a phrasal verb that means:
with no object, to be in progress/not done yet, or the same meaning as to continue. It is usually used progressively. The party is still going on, we are going on with the project.
with an object X, to consider X as evidence for doing something else or as a guide. I'm going on what she said, we've got nothing to go on, don't go on just what's in the book.
It can also still be used non-phrasally:
I told my sister to go on the stairs for the picture = I told my sister to sit or stand on the stairs.
Informally, up can emphasize this non-phrasal meaning:
I told my sister to go on up the porch and wait for me.
It also can be part of a "bigger" phrasal verb to go on about X which means to talk a great deal about X or excessively about X.