keep somebody on their toes
US /kiːp ˈsʌm.bə.di ɑn ðer toʊz/
UK /kiːp ˈsʌm.bə.di ɑn ðer toʊz/
1.
to make someone stay active and concentrated
:
•
The challenging project really kept us on our toes.
•
Our boss likes to keep us on our toes with unexpected tasks.