keep an eye on

Meaning

To watch someone or something carefully to make sure everything is safe or stays the same.

Examples

1. Can you keep an eye on my bag while I buy a coffee? US UK
2. Keep an eye on the soup so it doesn’t boil. US UK
3. We need to keep an eye on the prices. US UK

How to use it

Use keep an eye on + the person or thing. It means to check from time to time, not to stare. Do not use it for looking at something because it is beautiful.

Common mistake

Not: Please keep an eye to my bag.
Say: Please keep an eye on my bag. (The preposition is on.)