Assist, but don't grab it all! (4,4)
I believe the answer is:
take part
'assist' is the definition.
The definition and answer can be both to do with social activities as well as being verbs in their base form.
Perhaps there's an association between them I don't understand?
'don't grab it all' is the wordplay.
I cannot quite understand how this works, but
'grab' could be 'take' (I've seen this in another clue) and 'take' is found within the answer.
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is found in the answer.
The remaining letters 'par' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'but' is the link.
Can you help me to learn more?
(Other definitions for take part that I've seen before include "Participate, join in" , "Appear" .)