ENGLISH
REFERENCE

be onto

phr. v..
B2 Upper Intermediate Oxford

phr. v.. to discover something important or find out that someone is doing something secret or wrong.

phr. v.. to be in the process of discovering a significant truth, or to have evidence of someone's illicit or hidden activities.


SIMPLE

The police are onto the thief's plan.

CONTEXTUAL

I think the researchers are onto a major breakthrough with this new medicine.

COMPLEX

The investigative journalist realized she was onto something big when the CEO refused to answer her questions regarding the offshore accounts.

Particles
onto
Separability
inseparable
Pattern
be + onto + object
Usage

usually followed by a person (the suspect) or a noun like 'something' or 'a discovery'.

Teaching tip

distinguish between the literal 'on to' (movement) and the idiomatic 'be onto' (discovery); the latter is often used with 'something' to mean a good idea is forming.

Pitfall

He is on to a secret.He is onto a secret.while 'on to' is sometimes used, 'onto' as one word is the standard form for this idiomatic meaning of discovery.

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