keep somebody on their toes
US /kiːp ˈsʌm.bə.di ɑn ðer toʊz/
UK /kiːp ˈsʌm.bə.di ɑn ðer toʊz/

1.
manter alguém alerta, manter alguém atento
to make someone stay active and concentrated
:
•
The challenging project really kept us on our toes.
O projeto desafiador realmente nos manteve alertas.
•
Our boss likes to keep us on our toes with unexpected tasks.
Nosso chefe gosta de nos manter alertas com tarefas inesperadas.