catch up
No object
Reach the same level as others, or share news
I need to catch up on my emails.
Share recent news with someone
Let us meet for coffee and catch up.
Usage
'Catch up with' someone; 'catch up on' something.
No object
Nothing follows the particle directly. You cannot say it with a direct object.
Practise it
Add it to your daily practice or see every verb with up.
Further reading: catch up on Wiktionary (CC BY-SA).