get behind
US /ɡet bɪˈhaɪnd/
UK /ɡet bɪˈhaɪnd/

1.
tertinggal, ketinggalan
to fail to make enough progress or to be late with something
:
•
I've got behind with my work.
Saya tertinggal dalam pekerjaan saya.
•
If you miss a few classes, you'll soon get behind.
Jika Anda melewatkan beberapa kelas, Anda akan segera tertinggal.