Idiom
Keep an eye on
To keep an eye on someone or something is to watch them carefully, often to keep them safe or notice any change.
How people use it
People use it for watching children, pets, belongings, food on the stove, a situation or a person who might cause trouble: Can you keep an eye on my bag while I grab a coffee? It is neutral and extremely common. Keep an eye out for means watch for something to appear (keep an eye out for a parking spot). Keep a close eye on means watch very carefully. It does not mean using only one eye.
Also said: keep a close eye on, keep an eye out for.
Examples
- Can you keep an eye on the soup while I answer the door?
- The coach asked Ana to keep an eye on the younger players at the tournament.
- Doctors will keep a close eye on Grandpa's blood pressure after he starts the new medicine.
Where it comes from
The phrase is a simple image: your eye stays on something, so you see what happens to it. Versions of it have been in English for centuries, and keep an eye on in the modern sense was well established by the 1700s and 1800s. There is no special story behind it.
Check yourself
1. If a neighbor asks you to keep an eye on her house, what should you do?
Answer: Watch it and notice anything unusual. Keep an eye on means watch carefully to keep something safe.
2. What does keep an eye out for mean?
Answer: Watch for something to appear. Keep an eye out for means stay alert for something you expect to see.
Similar idioms
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