'Tis the way to pay attention! (3,2)
I believe the answer is:
sit up
'pay attention' is the definition.
(I've seen this before)
''tis the way to' is the wordplay.
'the way' indicates anagramming the letters (another way of arranging the letters).
'to' becomes 'up' (I can't justify this - if you can you should believe this answer much more).
'tis' with letters rearranged gives 'sit'.
'sit'+'up'='SIT-UP'
Can you help me to learn more?
(Other definitions for sit up that I've seen before include "Means to deal with corporation, maybe" , "physical exercise" , "may aid fitness" , "not to crash" , "form of exercise" .)