have something down pat
US /hæv ˈsʌmθɪŋ daʊn pæt/
UK /hæv ˈsʌmθɪŋ daʊn pæt/
1.
to know or understand something perfectly
:
•
After weeks of practice, she finally has her lines down pat for the play.
•
He's been working on that presentation for so long, he must have it down pat by now.